Yes, call your dad and ask for any help he can offer. Call your bestie, call your church. Ask for help and tell them why. The truth will set you free.
Yes, call a lawyer ASAP. You should anticipate that Mr. Deadbeat Dad will reform himself and try to be Disney Dad of the Year in order to hurt you. I've seen it far too many times, including in my own ex, that when the shit hits the fan they suddenly realize they've fucked with the Mama Bear one time too many, so they do an about-face and try to take the kids & avoid paying any kind of support.
SO PROTECT YOURSELF.
Call your dad.
Call your BFF.
Call a lawyer.
If you are at all afraid you need to call your local domestic violence group and ask for help. Don't think you cannot utilize these resources just because he didn't beat the crap out of you. DV isn't just bruises & broken bones. There are people out there waiting for your call. They want to help.