Ordering Catullus's works

51: The poem that I think came first among Catullus's works has to be Catullus 51. He sees Lesbia for what I can only imagine was one of the first times and is immediately awe stricken by her. This could either be taken literally that he saw her for the first time and thought, "By Jove! She is so amazing; I must make her mine!," or it could be taken slightly metaphorically. This would entail that they had a closer encounter (If you know what I mean) than simply running into each other on the street, and that he fell in love with her because of that.
2: Next, I would say poem 2 came in. At this point, Lesbia is playing with her bird. I chose this to be metaphoric towards her husband. She plays with him and acts like she loves him, but Catullus "knows" that she does it all thinking about him. After all, who's the cunning linguist here?
83: Then, I'd say poem 83 comes along. Catullus is now pretty confident of what he "knew" in poem 2, so he thinks it must go without questioning that Lesbia is just bursting at the seems with love for him and isn't even hiding it that hard from her husband, but he's too stupid to notice. Maybe, maybe not. Probably not.
3: This is where I think poem 3 comes in. Lesbia's husband dies. "How dare you kill him," says Catullus. "Why would you do something to make my poor, poor Lesbia sad. Can't you see she's already sad enough not being with me every second of every day?" Maybe he wasn't quite so blatant, but that's basically what Catullus is feeling in that moment (The character Catullus, not the poet).
5, 7: I think poem 5 and 7 come in here (in that order). They both compliment one another (I imagine 7 to be an extension of 5) in that they ask Lesbia to kiss Catullus an unreasonable amount of times. This is probably at a point in time when Lesbia's husband is dead, so there's nothing holding back the love between Lesbia "and Catullus." Yep. Just Catullus. She's not loving anybody else.
70: I'd put Catullus 70 here. He suddenly realizes that Lesbia doesn't really love him. Maybe he asked for her to marry him and she declined, saying that it wan't like that or something, but he found out. Then he gets mad.
8: He's trying to hold it together now. He's going to pull through this. Obdura. Who else will love her, now anyway... wait. WHO ELSE WILL LOVE HER!?! Wait a second, I bet Catullus isn't her only lover!

Oh no you didn't!

75: He can't love her, but he can't not love her either. #SoTornRightNow
85: This is eating at him now. He can't even write more than 2 lines.
72: Now he's getting a bit more logical as time soothes his emotional scars. He rationalizes it. The thing that is driving him to her so much is nothing but lust, while he has lost the R-E-S-P-E-C-T he once had for her.
11: Catullus compares himself to a flower being pulled in by the plow that is Lesbia. She's not a kind person who has gently picked him from the soil. She's a heartless plow that ripped him out of the ground along with dozens of others she cares no more about.
87: I imagine that some time has passed (but not a lot, maybe a couple years) since 11 now. Catullus is looking back with pride. He loved her so much. What he doesn't mention is how much she didn't, almost as a sort of way of saying that he's over her and willing to move on and be the bigger man while she is a heartless scumbag. He doesn't say anything about what she is, but he implies it in a way that makes him seem nice still. Genius!
109: Now I imagine quite a bit of time has passed. He is looking back on it and wishes just for that moment that things had turned out differently. He wishes the gods could turn back time and make her statements of love truthful, not like what they were in 70. Alternatively, this could be directly after 70, in the moment, as a more lustful, "GODS, PLEASE MAKE HER LOVE ME!!!!!!!!!!!"

Off Topic:

Catullus: I can't help but think of this every
time I read his name anywhere.

Balance in Catullus 70 and 72

Both Catullus 70 and Catullus 72 refer to an unreachable balance between what Lesbia sees between them and what Catullus sees between them. Lesbia has a more realistic view in which they are only enjoying each other's company for the sake of leisure. Catullus, on the other hand, refuses to accept that they are experiencing anything less than a full romantic relationship.

In Catullus 70, Catullus writes, "dicit: sed mulier cupido quod dicit amanti, in vento et rapida scribere oportet aqua (lines 3-4)," which basically means that men should be careful not to believe what their lovers say in the act and to "write [it] in wind and water," as it should figuratively flow away immediately in the ever-moving current that both wind and water possess. This is basically his way of saying that the passionate words Lesbia uses with him while bonding are to be taken cum grano salis. This fact is, of course following his claim that Lesbia once said that she'd rather be with him than Jupiter, a statement that he had believed to be true until he learned it to be untrue. Their strong polarizations of these thoughts show that they are not budging from their stances to find a happy conclusion, much like the House Republicans and the supporters of the Affordable Care Act right now.

In Catullus 72, Catullus basically backs up his claim in 70 by saying that he used to love her with a deeper emotional respect, but now he feels that she is undeserving of such respect, but he still loves her passionately. He says, "dilexi tum te non tantum ut vulgus amicam, sed pater ut gnatos diligit et generos. nunc te cognovi: quare etsi impensius uror, multo mi tamen es vilior et levior," (lines 3-6). When he says that he loved her as a father loves his sons, he's saying that he emotionally respected and supported her, and that it wasn't about the certain things they did together, as that would be quite weird between a father and his son. He then clarifies this by saying how even though he feels more passionately for her, she is worth less to him. He yearns for her physical affection more now, but he has lost that respect he once had as she shows herself to be a very popular person.

This struggle where Catullus wants her to be his lifelong romantic partner, but Lesbia wants only to have fun with him leads them to an awkward impasse from which neither side is willing to compromise at all (although if one of them does, it's probably going to be Catullus since Lesbia probably would care probably very little to lose one of her (according to Catullus 11) 300 lovers whereas Catullus would not want to lose the little he has with Lesbia). This balance will never be able to find a middle ground, either one must lose or neither can win.