Hi and welcome. And yes, it's OK. Painful, but you do learn from the errors and we've all made them (and keep making them).

It's hard to tell what's best without seeing any photos. If its a solid colour with some runs, then wait a couple of days for the paint to harden before removing the drip and sanding down in those areas. Thicker paint takes longer to dry, so do wait or you can pull off more depth than you want when sanding.

If you've got any single-edged razor-blades, then first get one and burr the edge over on a piece of iron or steel, then put a bit of adhesive tape over the two ends of the blade, so that 1/3 remains exposed. The tape raises the edge up off the surface, so if you then pass the blade over the drip area, with the burr facing the direction of scraping, you can scrape almost all the raised area off without affecting the surrounding paintwork.

Then once the blade isn't removing any more paint, you can strip-sand the remains of the drip. Cut some long 1-1.5cm wide strips of fineish sandpaper (say 240 grit), place over the drip area, put a finger on the spot to hold the sandpaper down, then pull the sandpaper out with your other hand so that you pull the length of the strip through under the finger. That way you only sand that area, not the rest.

As you are adding more coats over this later, it doesn't matter if the surface isn't glossy. In fact it's probably best if the whole surface is lightly sanded down to help get a flat finish (without sanding through to any primer layers or the bare wood).