Orgasm Help

So my boyfriend and I have been dating over a year and I have yet to orgasm. I’ve never had one and I try to not to stress about it because I know that makes it less likely to happen but I’m just curious of what I could do that could help the situation.....anyways so when my boyfriend is going down on me I feel like I get very close to orgasming and it feels really good and I feel this tension in my body like I’m about ready to and then like 2 seconds later what he is doing starts to hurt....like it becomes too sensitive it’s painful and I can’t take it and I don’t get that release...thoughts?? Tips???