Sexual frustration!!

I'm 19 years old and have never had an orgasm. I am very much in love with my boyfriend. He and I have been together for a year and a half and we both agree that we're not ready to have vaginal sex. But we have been doing oral for a while. By we have been doing oral, I mean I have been sucking his dick. He is the only guy I've done that for and it took me some time to feel comfortable but he was amazing. He had gotten his dick sucked before by several girls but never ate any of them out. At first, I didn't want him to eat me out because I was nervous about it and taught to keep my clothes on. But I started asking him to eat me out a while ago and now he's not ready. I am left in this awful place because I know he's trying. He tried to eat me out one time and it felt good but overall wasn’t a great experience for either of us and i know hes been looking up tips so he really is trying. Now we’re long distance and when we’re away, he talks about how he wants to eat me out but then we get together and suddenly he’s scared to again. I’m trying so hard to be patient but I’ve sucked his dick so many times I’m tired of giving. And I try to explain that to him but I don’t want to guilt him into it. My biggest fear is that he’ll think I would dump him over this. He’s asked me before if I would and i always tell him that having him as my boyfriend is way more important to me than being eaten out. But that I can’t keep giving him head as often as I do if he’s not giving me anything.

I know I can masturbate but it’s hard because I am always surrounded by conservative Christians (I go to a Christian college and my parents are super conservative and like to be with all of us kids every second) but when I do get the chance to masturbate I can’t get myself to cum.

Any advice on the boyfriend thing? Or tips for masturbation?