@TheHuth - Simply diving more without changing anything isn't going to correct your problem. After reading your descriptions, I'll encourage you (as some others already have) to check into your weighting situation. You have probably already looked to see that you don't have weights
Many people don't realize that BCs are inherently unstable in just about every degree of freedom available. If you have air in it and you are underwater, it will be trying to either send you to the surface or the bottom and roll and reorient you to either your side or head-up or head-down; anywhere except where you actually want to be. The more air that is in it, the worse it will be, and you'll have to constantly fight it to prevent these things from happening to you. These are just a few reasons why I like diving without a BC.
Your easiest and most stable diving will happen, when your BC is basically empty, or as close to empty as you can get it when you are underwater. Do a thorough weight check the next time you are out; about 500 psi in the tank, you want to display neutral buoyancy at about 15 feet depth with shallow relaxed breathing and an empty BC. If you can get the weight right for that situation, I think you'll find that the rolling to the side tendencies will be greatly attenuated.
Note - you can do the weight check with a full tank as well and then subtract the weight of the air from your weight belt. It's about 4 pounds for an Al-80, so about 3.5 pounds for a St-72 will get you in the ballpark.
If you minimize the air in the BC when you are diving, the size of the bladder is less of an issue. That said, I always encourage divers to go with as small a BC as they can get away with. For me, it is usually no BC at all for most of the diving I do. If you are inclined to get new gear, the BP and small wing is a good way to go for a recreational single tank diver. Freedom Plates and are awesome, if you can find one (not made anymore and kind of rare because people who have them don't let them go). With a BP/Wing, you can always remove the wing if you want to.