sick of this what is this? on going stomach problems..

ok for about 2 years now I have had on going stomach problems at full stomach ache my periods are very irregular I can go months without them or I can be in 3times in a month I'm 16 and have been on my period for 4 years,I was put on birth controll to regulate by the way I'm a virgin and u have not been able to take it because I'm always on antibiotics for throat problems I then had my tonsels out in October last year and I still get throat problems I'm booked in to see a surgeon next week again,anyways 3 years ago I went to see a gynaecologist and they said they didn't think there was anything wrong they didn't do no tests they just felt my stomach anyways,I always get stomach ache real bad soemtimes I can be bent over in pain,the pain can go from mild to severe anyways in febuary this year I had really bad stomach ache and hospital said it was my appendix so I had them out after I had them out I still had to keep going back in hospital because I was getting real bad pain in my stomach again they said it wasn't anything from my operation because they did all the scans etc anyways they said it was constipation,I have not been to school in 6 weeks and I'm in year 11 the school won't have me in at the moment because my stomach ache can come in suddenly and I'll just have to leave class,anyways 2 weeks ago I went school for the first time in 6 weeks and I was in class and I had a really sharp stabbing cramping,twisting pain by my belly button and under my lower stomach pelvic area and it was toward the right they rushed me to hospital I couldn't walk I was in agony,anyways they did all the tests and it come back ok they did scans and it was fine,I was getting so sick of this,and then they said my X-ray showed lots of stool stuck in my stomach so they gave me tablets to make me go to the toilet and wanted to see me in a weeks time I went back and my pains were still their and ild managed to do 1 poo and it was soft pellet and she prescribed more painkillers and tablets to loosen my bowels anyways she then wanted to see me again so I woke up yesterday and I went to the toilet and my wee was bright red jus red no lumps in or anything just red and I managed to do a little pellet stool and when I whiped there was blood in the tissue red blood and a lot of blood,I the told the doctor when I went yesterday and she did a urine sample and said I had a urine infection,my mom said why do I keep getting infections my tonsels,my appendix,water infections and also 6 weeks ago when I was in hospital I had a chest infcetion and blood infection and eat infection apparently,my mom said to the doctor isn't it about time you checked her bowels and they said no we are going to deal with this one thing at a time they needed to sort my water infection out first because it can lead to my kidneys and then they will sort my stomach pains out the pains just seem to be getting worse each time I have then,my normal stool I do a week is 2x a week also my mom said to the doctor do you think it could be endrometiosis because of her periods and that aswell and she said but I have had scans and my mom said no scans dont always show up and the doctor just replied by saying "oh ye" i have to go back in 2 weeks to see what's happening I'm in more painkillers at the moment and stuff to make me go to the toilet and a 3 day cource of antibiotics,what is going on my mom said endromentiossis effect all the organs aso my cousin has it my moms niece,please help someone:(