Candida and Birth Control issue?

I've been sick for like 2 or 3 months now. I had Candida apparently, and I took birth control while I had the yeast infection (I didnt know I had a yeast infection...i was given medicine to take twice---one the day i got it and the second one i took three days later, to get rid of the Candida i apparently had---) and I wanted to start taking birth control, but after 4 days of taking it I started getting sick. Like I felt faint and I wanted to vomit constantly and I honestly still feel this way. My doctor gave me a lower dose of BC but I don't want to take it. My first birth control I took I only did for a week and then I stopped. I was told that it can take up to 3 to 6 months for my body to get back to its normal hormone levels. And I started feeling sick the last day of finals for college. I feel it's ruining my relationship with my boyfriend that I've been sick. I don't want to go out anywhere anymore because I always feel nauseous and I can't help it. Some friends and family tell me to just not think about it but I cant help it cause I constantly feel pain in my stomach and such. I got blood work done (for another reason than this) and they said everything was fine. My boyfriend wants to take me out to dinner and to movies and other places and such but I can't even hold down a small salad or bread or crackers without getting sick. My doctor told me I was ok so I should not worry but I always do. I have no idea what's wrong with me. I was afraid earlier in this time period that I was pregnant but I went to my gyno and she said I wasn't when I took a test. Even the place where I got blood work done also gave me a pregnancy test and I am negative also...but why can't I eat anything without getting sick? I have a painful pulling in my stomach and such. I haven't had my period yet. My mom tells me I should be fine when it starts. I started it on April 29th and took my BC when I was supposed to. But I stopped the following Saturday cause of this happening to me. I was supposed to start at the end of may of course, but I started my period up again after I stopped my pills. Another 4 or so days. Then I was supposed to start my period on June 2nd but nothing is coming. I have cramps. I just want this all to go away so I can enjoy life. I'm 19 years old and I can't handle this crap. I have school, a boyfriend, work. I don't know what to do I have no idea what's wrong with me....does anyone know what might be wrong?!?!