masturbation tips?

I have never been able to get myself to orgasm. I have been sexually active for 3 years now and l feel like I have come close but I don't know for sure. Now my boyfriend and I are home from school and I haven't seen him in a month and he says he wants me to send him a video of myself masturbating and orgasming. I want to but I just don't know how to make myself get there. Please help