If you do have the built up crank pulley (harmonic balancer), paint a white paint line from the center out to the edge. Then see if the line stays aligned after you drive it a bit.

If it’s not that, the squealing was quite likely your belts. If it was, given how long you said they have been squealing, they are shot regardless of how new they are. Squealing for a half hour or so whenever you start out will have glazed or worn them to the point that they will not be likely to do the job.

If it's not mechanical, then you will have to check into the electric stuff.

Charley