Dancer, I've been there, and have just been discharged from the colposcopy clinic after the best part of 10 years or so back and forth due to abnormal smears and carrying HPV. Easy to say, and less easy to do I know, but don't panic.
Whilst smear tests are far from a thrillingly enjoyable experience, they detect changes early on, and more often than not, these changes return to a normal state by themselves. If they don't, then the colposcopy clinic will be able to offer you appropriate treatment and regular follow up examinations to keep an eye on what's going on.
The clinic in my local hospital was staffed by lovely people, and they went out of their way to put my mind at rest and explain everything that was going on and why, and what the follow up would be and so on. I had one lot of treatment (called cold coagulation - slightly odd name as it doesn't involve cold) and have had biopsies taken more than once as well, but it really isn't a painful thing, slightly uncomfortable sometimes, but compared to giving birth, it's a walk in the park! Maybe I'm a bit weird but I found it all quite fascinating (my clinic had a tv sized screen hooked up the scope and I could see what they were looking at - this is optional, you can look away!)
HPV is a very common thing, and there are multiple strains of it, different variants responsible for different things. It is one of those things that can be dormant for years, appear on a test result one year and disappear again on the next one. There may be some chance that you pass it back and forth with your partner, but then you may not - his immune system may well knock it on the head, and in time yours will too.
Don't worry, the good news is they've picked up on something being a bit out of kilter and will monitor it and treat it accordingly if necessary.
Sending a hug, I know it's a scary time when you get a letter like that, but honestly, try not to worry!