My gf (20F) and I (21M) have a problem we can't get past for some reason, are we just inexperienced?

For some context on our relationship.

We've been in a relationship for almost 4 years. We are long distance however. (We see each other about every other month for weeks at a time). Our long distance is a 2 hour flight which isn't that bad.

We generally have a stable relationship. I am supportive of her hobbies and interests and she is supportive of mine. Any problems that we have are usually sorted out that day or day after, as we are very open to talking and sorting it out asap.

I find that our family situations to this problem are irrelvent so won't include unless asked.

Now onto the problem that we have. It's about our sexlife. When we're together we have sex fairly often, I'd say about 4 out of the 7 days of the week on average, some weeks can be more some less. For context on this issue, I am her first sexual partner but she has had a boyfriend in the past(he will be relevant to the story) right before we met, which she did admit to doing stuff with just not any sex (vaginal or anal). For me I have had 1 sexual partner in the past but it was very brief so I have little experience. So when we started we were both fairly new(I knew a little bit more).

We do not have any medical issues that would cause any problems that we are aware of.

The problem is that sex sometimes for her can be very painful. I never force sex onto her, and have told her repeatedly, that all she has to do is say to stop and it stops right then and there with no ill feelings from me as I can't enjoy it if she can't. As an example, a few days ago we were both slightly stressed from the day and decided to be intimate to let some steam off. I started to try some foreplay but she wanted to cut to the chase. We couldn't finish because it was very sore for her to the point of tears. I immedietly stopped and comforted her. I believe this is because she doesn't let me do a lot of foreplay beforehand.

After this incident we had a talk. What she said was.

1. Sex is sometimes painful and this causes her to want to stay away from it sometimes. (We've known about this for a long time)

2. She sometimes has a massive urge to have sex and then its not painful. But sometimes when she doesn't have an urge is can also be painless

3. She hasn't came a single time from anything. She doesn't like masturbating and she always has a feeling of peeing during fingering or vaginal sex but always stops herself.

4. When she was 16 (so about her ex's relationship) she usually got horny quite often. But after that relationship she gets less horny and sometimes turns away from sexual contact.

5. Her ex treated her badly and their relationship ended very poorly towards the end (they were together for about 8 months and apparently barely had physical contact for about the last 2/3 months)

6. She thinks its because of my length that she feels pain. I am slightly above average but I don't see this being an issue when we can have sex other times either no pain. However, she feels no pain during fingering so she might be right.

7. Certain positions are more painful than others, for example missionary. However when she feels no pain during sex then every position is painless

At first I thought it was an attraction issue. But she's told me time and time again that she finds me attractive and I can really see it when it comes to non sexual encounters. She never hides me away from her friends and she always wants to be seen with me. Even when it comes to sexual encounters, she often initiates them.

Now she had mentioned that whenever the topic of sex is brought up she gets tense. She has mentioned that whenever we have sex, she somtimes gets tense as well. To me this seems like a psychological block that she has for sex that could be brought on from her previous relationship.

However, I'd like the opinion of people more experienced than us to weigh in on this.

Is it because of a mental block she puts on herself?

Is it a physical issue that we have?

Is it something we are doing wrong when preparing or during intimacy.

We are willing to give any information that is neccesary.