I didn't pay my supervision fees. Its been hard for me to find jobs, no one would hire me because of my record. Will I go to jail once I turn myself in to my po?

Possibly. Possibly your probation will be extended.

Thanks.

Do I need a lawyer

That's never a bad idea. I just don't know that it will help you. If you can't pay your fines, you can't find employment, I see no way except to give you jail time - unless you see an improvement in your financial situation.