Orgasms

So I'm needing help. My boyfriend and I have been together for about 6 months now and every time we see each other and have a chance (which is very often), we have sex. I don't mind this being the case, but I have never "gotten off" with him. We are each other's firsts and the sex is fantastic but I feel that I have a sexual frustration that builds up sometimes and this makes me emotional and annoying, even to myself. My boyfriend wants to help me have a O but I honestly don't know how with another person. I know I can get off by grinding on a pillow and such, but I have never been able to use my fingers or anything else for that matter to work. My boyfriend is willing to do what he can you help me but I don't know if I'm able to with him or not. Does anyone have any suggestions? We are both around 18 so still young but I'm curious to see what more experienced people say on this topic.