Thanks for reaching out! This is a tricky situation and definitely requires a delicate and respectful conversation. I'm glad to hear you've done some research on Google in order to learn some ways that may make intimacy less painful.
I have been in this situation as the person who has endo and a lot of pain, and I can tell you the pain alone affected my libido, but so did many other aspects of the disease. I definitely experienced guilt about not wanting to be intimate.
I would bring it up to her and ask her when would be a good time to talk about it...I wouldn't expect her to want to talk about it right in the moment you bring it up. Give yourselves a good amount of time in a low-pressure situation to discuss it. You could let her know about your research and share with her what you learned. And then see what she has to say about it. Perhaps she's done similar research or has thought of some ways to alleviate the pain herself.
It could also be the right time to seek the help of a couples or sex therapist who is well versed in pelvic pain who could help you work through this.
For myself, I know that pelvic PT was somewhat helpful, but when I was having my worst symptoms I was in too much pain to even consider being intimate. My gynecologist suggested CBD suppositories, but I didn't get to the point where I tried them, so I can't speak to their efficacy.
I think what would have helped me in my situation was patience and a genuine attempt at understanding from my partner. And a sustained effort at open communication. We let things go unsaid for a long time and it became harder to talk about. Finally, don't put any pressure on her to be intimate if she's not feeling open to it. There may be other ways to connect, like cuddling, or kissing, or mutual masturbation that achieve the physical intimacy without intercourse. Ask her what she thinks would work for her so that you can maintain physical intimacy.
I wish you luck and please feel free to ask further questions! ~Katrina, Endometriosis.net Advocate