It's hard to say without knowing everything that happened. It sounds like you're not preparing them for the kiss and that can come out as a DLV.
What steps do you follow before going for the kiss?

For the girl you sucked her tits it sounds like you did something to turn her off and that made her change her mind..

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Move to another town. I used to live in a small town too and it makes everything more awkward but I still recommend you to approach all the hot girls in town before you move.
I regret not approaching more when I was there since it was a missed opportunity.

If you have to stay in your town mix cold approaching with social circle game. The worst thing about small towns is that most girls already have boyfriends so that makes everything more difficult.

I added a more details about my interaction with her in the post. I won't be going to that class in a couple of weeks so I won't see her for a while.
I wrote my favorite writer because she told me she's a writer and also writes poems while we were talking.

The part of the condom surprised me. How do you avoid getting stds and knocking the girl up?