Accepting positions and interviews..

Ugh. I'm stressing over this and I'm hoping that I can get some help putting it in perspective. I just graduated from my FNP program in May and have a couple of lines on some positions. A big thing for me is to have my student loans paid.

Here are the places I've been talking with:

Cardiology: most likely not going to pay my loans but definitely in an area that I love. They've been slow getting through the interview process with me so I'm not really entertaining them. They do keep calling though.

Primary Care 1: Yes, I do want primary care. So this place; love the staff. The $$ is not great, but more than I'm making as a RN. Perk: federal loan forgiveness. I could have them all paid off within 5 years and be free to move on because the non-compete is minimal. Contract is for 1 year.

Primary Care 2: Further drive. Interviewing next week. My friend is going to work for them and gave them my name. They are very interested in me. Also qualifies for federal loan forgiveness and non-compete is minimal. Contract is for 1 year. Much more opportunities to make more $$ at this office.

My problem. I verbally told PC1 that I was accepting their offer. This was before I learned of PC2. PC1 is supposed to me sending me a contract and haven't signed anything yet.

Is it awful of me to back out of PC1 (as long as my interview goes well?) How unprofessional does that make me look? Guilt and a sense of responsibility are killing me!