Lol, man, you're just having all kinds of shitty luck huh? Anytime you have a serious leak problem, you'll experience a loss in pressure. Take a oil pressure gauge and check to see what the current pressure is. Oil pump shimming can be done to increase the pressure but that won't help you if you have a leak. In fact, that'll work against you as the increase of pressure will result in an increase of leakage. Start with the front main seal, as it needs replacing anyway. Then work outward from there. Testing the oil pressure with a gauge will help determine whether or not the oil pump needs to be replaced. Normal pressure @ 3000 rpm is about 50 psi, I believe (someone double check me).