Tommy, you might be able to add a regulator to your compressor. It just depends on the fittings. If they are so that you can just screw a regulator on then it would only be a $20 fix and give you a more usable compressor. If you had to buy a bunch of adapters and stuff it might not be cost effective or worth the trouble.
I think most of the "Hobby" type compressors that don't have a regulator are set around 30 - 35 psi. If so that's the cause of most of your overspray. I paint at about 15 or less and I think most others do as well. At 30 you have to back so far away from the surface to keep the paint from puddling and running that most of the paint just blows everywhere. At 15 or less you can get real close to the surface and the paint doesn't blow everywhere.