I [M21] am unable to have sex with my girlfriend [F21] because of her endometriosis.

My girlfriend and I recently celebrated our one-year anniversary in October and just moved in together in December. While it might seem like we rushed into things, I assure you that our connection feels absolutely right. A few weeks into our relationship, she informed me about her endometriosis, but I didn't fully understand the implications it could have on her body at that time. Nonetheless, it didn't hinder our intimacy, and we were intimate almost every week. I had communicated to her that sex was significant to me, and it appeared that she felt the same way. Unfortunately, as I settled into our new living arrangement, her condition worsened. Since moving in, we’ve only been intimate twice, both in December, and each time lasted about 30 seconds to a minute because of her severe pain. The last instance was particularly tough as she ended up in tears, feeling guilty for not being able to meet my needs. She started a new birth control in November that helps manage her daily pain but has drastically reduced her libido. I’ve suggested trying different positions, using lubricants, and other options, but she isn't interested. It’s now at a point where I can't persuade her to try anything new because she fears it will hurt, and I often feel guilty, as if I’m the one with an unhealthy fixation on sex. I feel a significant sense of guilt knowing she can't control her situation. Leaving is the last thing I want, but this has created a feeling of disconnection in our relationship. I'm looking for advice or insights. Are there other couples who have faced similar challenges? Thanks for your support. TL;DR: How can I maintain a sexual connection with a partner who has endometriosis?