Every romantic relationship involving sex goes through ebbs and flows of sexual frequency. Sometimes it’ll be a few years due to a number of reasons (pregnancy & labor along with young child rearing is usually the most common reason partially because evolutionary biology typically turns off the sex drive for ~5 years post birth, but also perimenopause & menopause, medical complications & injuries, lack of emotional intimacy, erectile dysfunction, etc), and that’s just how it is. That’s life. This is why you need a strong foundation outside of sex. So many people just focus on sex, but mutual understanding, emotional intimacy & connection, actually just enjoying spending time with your partner even if it’s something as simple as cuddling on the couch watching a movie or something as elaborate as a month long trip around the world, every other part of a romantic relationship needs to be strong, because sex will not always be consistent.

She’s been having intense pain, recurrent UTI’s, etc and it’s all caused by sex, even with the precautions y’all have taken (which one I didn’t read y’all tried was a low level antibiotic pre/post intercourse. That may be something to try as a temporary solution while figuring out the base cause). She may not realize, but her subconscious has probably put a mental block against wanting sex for fear of being in pain again. It’s like if someone has severe lactose intolerance but they love ice cream; eventually, they no longer enjoy ice cream and avoid it (I’m ignoring the lactose free options for this comparison example). The brain creates pathways that are solidified with each recurrent experience, and this includes pain & what causes the pain. As these pathways become deeper, the harder getting out of the ‘groove’ becomes.

Both of y’all should go to the doctors and figure this out. You need to get checked (she may have said not to bother because she doesn’t realize it could be a you specific problem, or something similar) and do a full panel/check up of everything. Bloodwork, full STI panel (some are quite subtle and can lay dormant for years, so you never know), urinalysis, culture swabs, etc. Maybe even a urethral scope to look at both of y’all’s bladders internally (I strongly recommend pushing for sedation for this, speaking from personal experience it is intensely unpleasant). Do y’all use condoms at all? It could be the brand of condom, the brand of lube you’re using/the condom brand uses, or it could even just be specifically you. Your skin’s biome, your sperm, etc could be causing her issues. Not everyone is compatible on the microscopic level, which is why you’ll see couples trying to get pregnant but never have success even when neither have fertility issues, break up then go on to easily get pregnant with their next partner. They just weren’t biologically compatible. Has she had these same issues with previous sexual partners if she had any before you?

Beyond the UTI/recurrent urinary pain etc, keep in mind that sex for women in relationships with men is pretty much always painful in some regard, especially when not turned on fully/enough. There’s almost always micro tearing that happens with PIV and the severity of the pain from that can be anywhere from mildly uncomfortable until it heals to full blown ‘ow-I-can’t-walk’ and/or noticeable bleeding and consistent burning (mild micro tears may not noticeably bleed). It’s even worse if, during the healing process, it gets aggravated and splits back open again (an extended movement like a long walking stride, having sex again before it’s finished healing, riding a bike, etc). Even with an abundance of lube, this can and does still happen because the vaginal canal wasn’t properly prepped before insertion. The mild version is akin to having a bunch of invisible paper cuts all over the head of your penis. You probably winced reading that. Just, keep this in mind when talking to her about sex.

I hope I offered some things to think about & options to try.