Sarah, when you say "any more" I assume that you could in the past. Obviously something has changed so the trick is to figure out what.
I'm going to assume that this is not a new BF and that he has been able to do the trick in the past. If that's not the case then he'll have to learn what you like. Has he grown bored of the whole thing and is no longer giving it the old college try, or is he doing the same things he's always done with fewer results?
OK, you seem to prefer clitoral stimulation. Sometimes hormonal changes can affect the sensitivity of the clitoris. Have you noticed that this is more or less of a problem at different times of your cycle?
You'll have to do some experimentation (that's the fun part) to find out exactly what the problem is. I can tell you that stressing about it will only make matters worse.
I can give you a specific technique for your BF to try that might help, but I won't post it here. I'm a health educator not a sex coach and this is an education site. Send me a private message if you'd like.
I would try to masterbate alone and try to have an orgasm that way. maybe your boyfriend is not doing it right anymore.