I NEED HELP

so I’ve been dating this girl and she’s amazing in every way the, the only part is the sex is so frustrating because I don’t know what to do help her or make her relaxed. When I try to give her head she squirms and says that she ticklish and honestly when we try she usually just kicks me off. When we have sex I can’t put it in because even so much as the tip hurts, we tried lube and nude dry humping that works but it takes like 30-40 minutes and then we can get going, and today I’m afraid with even that it still “hurt” her. Any position we do it hurts her and I feel bad because she will say no no and I’ll stop and she gets upset because she can’t. Also we are in our early 20s. So idk im her 3rd ever partner sexually and as well missionary is her least favorite position because it just hurts. Like I said the only way we have sex is if we dry hump for a while to get it going; but like I said today it was to no avail because it still hurt. I don’t know what to do and it’s frustrating both of us any advice helps!