This is common and it's nobody's fault. A good partner should be understanding and not resent you. I agree to see your ob gyn to rule out any potential causes. Sometimes, it's a matter of finding the right type and length of foreplay to make sure you're ready for piv. Some women do need at least 20-minutes of warm up time, while others don't need as much. Some people find out that they have latex allergies that makes vaginal sex painful. Sometimes, a couple has to find the right type of lubricant that works for them.

One thing to try is to purchase a sex toy (if you haven't already) to practice being relaxed with penetration at home. Inserting the tip and letting it rest can be a good start. If you can't get that in, there's the option of pelvic floor therapy that maybe your doctor can recommend.

I understand the idea of feeling incomplete without penetration, but the other stuff you're doing is just as valid. Some newly sexually active people learn that they do prefer other acts over penetration, and that's okay.