Mildly [NSFW] Lost my virginity today, not sure how I feel about it

Some background: I turned 18 early on in 2015 and since then I've had around 6 or so hookups with guys off of a certain gay-dating app. Each time was more enjoyable than the last, and I felt as though I had really gotten into the flow (for lack of a better word) of my sexuality, in terms of what I like and what I don't.Today, after chatting for a while with a pretty cute guy on the app, and after mentioning that I was, in fact, a virgin, he asked me if I would like to come over and try topping. While I was hesitant at first, mainly since I had somewhat made up my mind that my first time having intercourse would be with someone I had known for at least a while, I agreed and we arranged a time to meet up.I got to his apartment and I went into the bathroom to wash up a little (I was sweaty from the walk over, it was kind of hot outside), and then went to the bedroom and started fooling around. After the usual making-out/oral/foreplay type of stuff, he stood me up, handed me a condom and some lube, and bent over the bed. I put the condom on, lubed up his butt and my cock, and for some reason I found that I was losing my hardness. Through my embarrassment (and his encouragement at it being my first time) I got hard enough for me to put it in him. After a few pumps I slipped out, and found I had gone soft again.Now, I'm unsure if it was because of my nervousness at it being the first time, or the realization upon arriving at his apartment that he wasn't necessarily as good looking as he was in his photo (which may seem shallow). Nonetheless, he was really kind about it and just laid me down, ass up. He then asked me if I'd like to try bottoming, I was hesitant because I know that before bottoming you should maybe try fingering, and sort of stretching the hole, as well as making sure there's no poop up there. I explained to him that I hadn't pooped in the morning, and while I'd like to try bottoming, I don't think it'd end up well. He managed to convince me it was okay, and he slowly put his cock in me.Now, it was pretty painful, and even when he slowly started thrusting, the enjoyment on my end was minimal. He saw I was uncomfortable and pulled out...only to find some poop on the tip of the condom. I apologized profusely, but he said it was no big deal and went to the bathroom to dispose of the condom. Upon his return, he bent over and told me to try fucking him again, and i did. After a certain point however I just gave up, and I'm still not sure why I couldn't get hard, so I slipped the condom off and started stroking my cock, which got hard pretty quick. He asked me to rub it against his hole, and I did. After that, he told me to put it in.At this point, my brain was saying "No. No. No. Be safe, condom only, don't do it" but my other, smaller brain, told me to just go for it. Stupidly, I listened to my smaller brain and went in. He told me he was clean, but I do still have that fear in the back of my mind of catching something. I ended up finishing on his back, and ended up awkwardly leaving.I really don't know what I want to get from posting this, maybe I just wanted to get it off my chest. Thanks for listening, and I guess any advice for the future is greatly appreciated.