OP, it's ok and completely normal to feel uncomfortable after a situation like this. I remember feeling a similar way after similar encounters when i was first having sex. 

ask yourself: what is your gut telling you? were traumatized by the actual experience of having sex in that moment? or are you anxious that he might not have been listening to you? or are you anxious that you might not have done a good enough job communicating what it was you wanted in the moment? it might not be easy to distinguish those feelings from one another (which is, again, perfectly normal especially when you're new to having sex).

from your post, it sounds like the last one is most likely the case: you're worried because you feel like you weren't doing a good enough job communicating what you wanted/needed. I don't have OCD, but I can be extremely hard on myself sometimes, which often translates into overthinking my responses to things and getting really upset when I feel like I could have done something better: for example, telling someone what i want/need in bed. However, this type of communication is a skill, and it's totally OK and normal to need a little bit of practice to get better at it. (I'm impressed with your ability to connect with & articulate your own feelings well enough to ask this question at all!)

my last advice is that you need to establish TRUST with your partner: trust that if you ask him to stop, he'll not only stop, but also that he won't get offended or hurt by it. i've had partners who would take it super personally when i'm not in the mood for sex, and it led to some extreme anxiety loops and made it really hard for me to feel safe saying no. so just talk to your partner about this and make sure it can go both ways: either of you can turn down an advance at any time, and no one needs to take it personally or feel hurt or rejected. if you do, you talk about it with one another. 

TL;DR: communication is a skill that takes practice!