Every paint job will require a wet sand and buff if you want it perfectly smooth. I have never heard of a complete all over paint job to come out without any orange peel. Some jobs on vehicles can come close enough to pass the untrained eye as a factory job, but even factory jobs on 500K vehicles have the peel. Hell, even show cars have flaws that go unnoticed to the untrained eye. The sanding and buffing helps to level whatever hills and valleys there are to really bring out the shine of the clear. With your color you would have been just fine stopping at 1500 grit. Something to keep in mind is that when wet sanding you need to keep as much of a contsant flow of water over the place you are sanding, and use a little liquid dish soap in the water bucket that you paper sits in. That helps the paper glide over the surface much better. A little trick you can do to get more life out of your wet sending paper is to let the paper soak in the water at least 15 minutes before you use it. Trust me on that one. You want to keep flushing out the debri with the water where you are wet sanding so you don't end up putting more scratches in the clear than you started with. If you accidently pick up a grian of sand(or even smaller) and rub that on the finish for a while you will never see the destruction until you buff it. That's when you get this really heavy sinking feeling because you know you have to go back and sand agin.

P.S. you didn't screw up as bad as you think you did. You should see some of the paint work that rolls out of the paint booth at you local Econo, fact-o-bake, macco, etc. Working with what you had, and the conditions you were in, i'd say you did pretty darn good for your first time.