NuvaRing and pregnancy prevention

I'm 21 and I have never been on any kind of birth control method. I decided to get on the Nuvaring because I had a pregnancy scare. My boyfriend and I have only ever used condoms, but one broke and that was enough for me. I've been on the Nuvaring for about 2 weeks. I normally get my period every 35 days and the only cramping I ever experience is the first and second day of my period. After the first week I noticed I had some light cramping and thought nothing of it, but as time went on the cramping only seemed to be getting worse. I told my doctor about it and she advised me that it was probably my body trying to get used to the ring. Never having used birth control before, I tried not to worry. Then, I noticed some other changes that concerned me since it wasn't like me to feel that way. Aside from the cramping, I had been feeling very depressed about my life and where I was headed for some reason, and my sex drive was depreciating. My boyfriend noticed of course and I had no idea why I was feeling that way. It wasn't until I came across this website that everything started to make sense. I thought I was the only one experiencing these changes. I'm definitely going to change birth control methods. I just don't know what is the best out there. Can anyone help me?