1978 Volkswagen Beetle Jerks while driving

Engine Performance problem
1978 Volkswagen Beetle Automatic

The problem started about a week ago but it just happened from time to time. Now it happens just about all the time. The car just jerks violently then goes smooth and just repeats this process the whole time.
Ive heard someone say that it might be the fuel filter being dirty. I know very little about cars but I don't have the cash to fix it at present, so if I could fix it myself that would be great.

Ive recently put in a new fuel tank but made sure it was clean and I cleaned it out, could this have something to do with it?

All help appreciated.