I just replaced a leaking gas tank and it ran fine for about 15 miles. Then I lost all power when I stepped on the gas. the engine was still running but would not accelerate. If I turn the engine off for a few seconds I can restart it and it runs normal for a few miles the the same thing happens. Is the fuel filter plugged or do I have bigger issues?

How muck fuel in tank?
Check fuel filter and fuel pressure.
Post back fuel pressure readings.