I'm so desperate!! Please help!!!

This is going to be long but please read! I'm very desperate at this point and really need some advice!

So for around two years now I have had reoccurring UTIs. This started around the time I had sex for the first. My boyfriend and I had messed around for a year before that without any problems. We have had sex with and without a condom. (We use skyn condoms)

Over the two years I have alternated between 3 types of antibiotics. At first everything was fine aside from one of them which caused me to spend the entire night with horrible stomach pain and vomiting every hour. Eventually one of the other ones started to make me vomit all night with stomach pain as well. Then the other caused me to have on going diarrhea.

I decided to go to a urologist who then prescribed me medicine to take before or after sex. At the appointment I got tested to see if I had a UTI (which they never told me if I had one or not) they also looked at my chart and said some of my more recent tests that I had taken before college had come back negative but had blood cells in my urine. Although I have tested positive before with Ecoli causing my UTI. They never gave me any medicine to fix my current UTI which is growing worse by the day. Right now I only have the ones to prevent the UTI after sex. I would take some of the medicine my normal doctor gave me. (I have a full prescription I haven't taken since they make me sick and I would hoping the urologist would help) although being up all night sick for a week is pretty impossible since I'm in college.

Also at the urologist I got and ultrasound done and nothing looked wrong. Yet I get a slight aching on my left side but my normal doctor said this could be from not drinking enough water. For a while when I got UTIs I pushed the water a lot now though to get through classes I can't drink a lot because if I do I have to go to the bathroom every five mintues.

For the record I always wipe front to back. I pee before and after sex. I cleaned myself with a warm washcloth before and after sex. I drank a glass of water after sex. I asked my boyfriend to clean himself really good when he showered. I also tried cranberry pills and things even though natural methods almost never work for me.

I have also been tested for HIV and I think one other sexually transmitted disease. I doubt I have one though. My boyfriend and I have a 3 almost 4 year relationship and we literally text all day if we can't see each other or spend all day and night with each other. We were also both virgins the first time we had sex.

So basically what I'm asking with this long ass post is...is there anyone who knows what I should do or has been through this?? It's really getting in the way of all aspects of my life. My mother seems to be convinced it's my birth control causing it but she doesn't know I'm sexually active (simply because she's religious and I'm looking out her feelings although I wouldn't mind telling her. All my doctors know) I also saw online that there is no proven link between birth control and UTIs. I really like my birth control and it has improved my life greatly so I really don't want to stop but I'm willing to try once summer hits. But please!!! If you have been through this help!!