How to orgasm during sex?

So I am 17 and I’ve been with my boyfriend for 2 years and 3 months. We recently had sex for the first time in September. I have never reached an orgasm from him... the only way I can orgasm is if I use a vibrator/stimulate my clit. I ask him to do it but it doesn’t feel right.. it kinda feels rough and uncomfortable. When we have sex, it feels amazing but I know I’ll never reach an orgasm from penetration. Is there any way I can fix this? We usually stick to missionary (with my legs up kinda over my head lol). Ive tried being on top but it all feels the same. What are the best sex positions? We have tried doggy but it simply doesn’t work because he is 6’5 and our bodies don’t fit together that way.