I know it's long but please read. I'm desperate for help.

I am 20 years old, have been with my boyfriend for 2 years and have only had sex with him.

We began having sex in summer of 2016. I have always made sure to drink a lot of water & pee before & after sex. But It wasn't until Jan-Feb of 2017 that I got my first UTI. I got one & after a week, I went to the dr, got meds & the symptoms subsided until the meds ran out... 3 days after the meds ran out, here I was back in the Dr again, this time they ran a second urine test, confirmed I did have bacteria in my urine & prescribed another antibiotic. I took it, everything felt better, until a day or so after I finished the second round of meds. I was back to frequent urination, burning when urinating, etc. third times a charm right? Back to the doc I go, (mind you since the first time i realized I had a uti, I had not had sex) they ran a 3rd urine test, confirmed bacteria in my urine, prescribed stronger meds. As the previous two visits, symptoms subsided, 2-3 days after I finished the third round of antibiotics, here came the symptoms again. Back to the dr... if you've ever had a uti, you would understand how painful & irritating it was. This time, the urine test showed no bacteria...WHAT?! The dr then decided that the uti was probably so severe it had my bladder severely inflamed, still causing those symptoms. He prescribed uribell (spell check) to calm & soothe my bladder. Then worked, for the 10 days I took it. Even 2-4 days after I finished the meds. After this has went on SO long, I finally was able to return home from college & visit my primary dr. She ran a urine test, found no bacteria & agreed with the previous dr that my bladder was probably severely inflamed & suggested I needed to "retrain" my bladder, as the uti had went on for basically a month & my bladder might had gotten used to frequent urination. All has been well (having sex & all) until around the first week or so of July. Had sex, then a few days later here came the uti symptoms😭 I saw my primary doctor, she ran a urine test, confirmed bacteria & prescribed antibiotics. Finished them up & symptoms were gone.

Have had sex a couple times since & been fine.

This last Saturday night (29th), we had sex. As a precautionary measure, I took Azo defense & 2 cranberry tabs before sex & lots of water. As always I peed before and after. The next morning I took azo defense & cranberry tabs. Sunday night I took 2 more azo defense tabs. This morning I woke up fine, have been fine all day & tonight when I laid down in bed, I had the sudden urge to urinate. When I went to the bathroom, there wasn't much there & after emptying my bladder I still feel the urge to go.

Has anyone had uti's this frequent? Is there an alternative treatment I haven't found that actually works? Is everyone else's just this bad at night, I don't notice it as much during the day?

Is there an alternative preventative for this?

It's so frustrating & I can't even enjoy sex because im worried about getting a uti every single time.