Me and gf are Unable to have sex, need advice

Me 20M and my gf 20F know each other from almost 7 years, we were friends earlier and now its almost been close to 2 years to our relationship, its good we are both dating to marry and everything is good but whenever we’ve tried for sex it never works out, it once did but never again, the once it worked out was when we went raw, she still sometimes asks me that we should do it that way when it doesn’t work out with condoms but i deny knowing the potential risks as i don’t want to ruin either of our lives, sometimes im able to get it in once sometimes even that doesn’t happen its just the tip and she’s so much in pain that i never continue and she herself also asks me to stop, we’ve tried everything plenty of lube, plenty of foreplay and idk what not, she is kind of a shy girl so she doesn’t know much about all this, she doesn’t even masturbate, I’ve asked her numerous times that she should do that as she would get to know her body better but she says she doesn’t feel like it and never does that also and also she doesn’t get me off by other means too like I’ve never asked her to do it but still ig she should at least do that as at the beginning of our relationship she learned how to give HJ but she always get tired with it and she feels that BJ is disgusting and never done that and i never got one so yeah i never get off its always building up and then it leads to nothing, that leaves me sometimes frustrated and asking myself what is this where am i stuck, ive never said bad things to her about it and never will i always console her and request we should stop trying if it hurts as i don’t want u crying and all, idk we cant go to the doctor as we are still too young for that and she wont agree for that, so that basically means i will have to wait for sex for at-least 5-6 years as we wont be marrying before that and then we will go to the doctors and all idk i love her i dont want to leave her for sex but sometimes im so frustrated that i cant help those thoughts, also she initiates sex almost never its almost always me but most of the time she is interested idk what to think what to do, help me please