Do you still have the old plugs and wires?
It's hard to diagnose over the internet but it sounds like it's running on 2 or 3 cylinders.

Pull all the plugs.
Try a known good plug (probably the most tan and dry one that's currently in the engine)
Try that plug in each plugwire, holding it against the engine block to earth.
You are looking for a strong blue spark from each wire.
This will eliminate the distributor and coil as the issue.

If all the wires give a good spark from the good plug then try your other plugs in one and see if all your plugs give a good spark.
If there's a wire that doesn't give a good spark with a known good plug, then the wire is the problem
And same goes for the plugs, if you get a good spark on one plug, but no spark on another then the plug is the problem

That's a basic way to to it, sometimes the issue isn't immediately obvious (plug wires that fail when hot, plugs that spark in one orientation, but when in the engine are the wrong way, or a weak spark that gets blown out under compression) but don't worry about that for now.

The other possibility is that the timing is out. Did you loosen the distributor at all?