I also have HPV. I'm 36 and was diagnosed at 21 (was with my then boyfriend at the time and to this day, I never knew how I got it since I had only had sex with one other person before him and used condoms with him and also my then boyfriend).
It was pretty devastating and my boyfriend at the time wasn't very understanding. I actually just recently had a horrible experience with someone I told about my HPV and he made me feel horrible and tried to make me feel "dirty" (and then I came to find out he had been lying to me that he was married the entire time-nice, huh?) There are some big jerks out there.
Anyway, you are lucky you have an understanding fiance. Also, I'd like to slap your OBGYN's nurse because the doctor should have told you the diagnosis in PERSON! (not over the phone). That's really bad.
I went through all the same emotions you are going through and it helped to do research and to have good OBGYNs. I did have abnormal paps, colosocopies, biopsies, pre-cancerous cells found but I also had many years where my paps came back negative for my HPV. I suggest you take care of yourself (don't smoke, don't drink a lot, exercise etc). I've been a long time student of yoga which I think has really helped me. Also, when my life started to be stressful that's when my HPV showed up again in my paps (and I wasn't sexually active at the time). Also, I had the same boyfriend for almost 7 years and have never been sexually promiscuous. One of my nurse practitioners have told me that even nuns have been diagnosed with HPV (and they definitely are not sexually active ha!)
Don't beat yourself up and you need to start talking to your boyfriend about your feelings (when you feel ready). It will affect your relationship if you don't share with him (especially your sex life). There are a lot of support groups out there online and a LOT of information.
I've dealt with HPV for a long time and I've had my ups and downs (physically and emotionally) but I just suggest you take care of your health and stay on top of your OBGYN exams and also have good care! It does get better, let me assure you

Best of luck!