Sex is painful

I have been with my boyfriend for 3 years and he is who I lost my virginity to, about a month into our relationship. Vaginal intercourse has always been painful for me if it lasts for more than a couple minutes. It’s a burning, sensitive, closed off feeling. I would like to add I have been tested and I do not have an STD.

Around 2 years ago is when it was the worst. At one point we had sex and then went out into public and my vagina started burning so intensely, we had to hide in the car because I couldn’t hide how bad it was burning. I literally just wanted to shove ice up there.

The emotional part of this is that I love having sex with my boyfriend and desperately hate how problematic it is. I don’t know why it feels like my vaginal walls are closed off when I’m so incredibly into what we are doing.

Ive looked into Vaginismus, but it seems like the causes tend to be described as a fear or anxiety of having sex. That’s not what I’m feeling, so I’m very confused.

Has anyone else experienced this or has any advice? I would really love to see a doctor but I’m without insurance so it’s definitely difficult.

EDIT: we use lubricant and I get plenty wet often. It does not help much.