Maybe both. If you are nervous, you could be dry or tense, which would make it more difficult for him to enter. However, if he is afraid of hurting you, he might not be trying to enter all that much or he could be losing his erection because of that fear. You could try buying some water-based lubrication at the store.

are you sure??? Because I found out he does drugs, is that affecting making him weak????

Anything is possible, but I doubt it. Most drug users can have sex without difficulty, at least while they are still fairly young.

Out of curiosity, do you engage in a lot of foreplay? Are you fine with manual sex from your partner? If so, this may sound weird but a friend of mine tried it and said it helped her a bit, try purchasing a dildo and using that during foreplay. Let him do it a little at a time, go slow, and as you are comfortable with that, let him try again (if you still want him to).

Well, the thing is that we use to do a lot of foreplay, and I think it's better than the usual way, for I get all dry, and ....well, nothing happens, actually, he tried 3 more times, but not lately I didnt want to anymore, but I'll try that. I hope he still wants to, jeje.