I'm no pro, but it sound like your 'slice' to the left is a hook. (Are you right handed?)
If you're getting blisters, try to loosen your grip a little, and don't try to KILL the ball. Swing slow. It will feel too slow. The key is, get it straight. Once the ball is going straight, then slowly, gradually, incrementally, (get the picture??) add power. VERY LITTLE at a time. I went from a 100+ player last year to a low-mid 80s. Hell of a pickup if you ask me.
Basically when I started, my goal was to kill the ball. If it didn't go 280 yards, I was pissed, but it NEVER went straight. I got a 1/2 hour lesson and was told to stop killing it and just let the club slowly swing itself. I was only hitting ~230 yards, but they were in the fairway. What I learned was that the 50 yards I lost was probably 30 yards better than before because I didn't have to contend with trees and going straight is much better than long and 2 fairways over.
Did any of that make sense? Hope so.
As for a hook, well, my problem is a slice, which i attribute to starting wide with the swing and drawing in to give the ball a spin that will go right. A hook would either mean you are starting your swing too close to your body (off plane) and ending too far away from the normal swing plane. Also, follow through. Don't stop the club after contact. Always keep your head down. If you are looking at the ball, you will probably hit it. You should be able to look up at where you wanted the ball to go and it should be there. (That is if everything else is done properly.)
Just remember, think slow, calm, and smooth.
OK, there was a 30 minute golf lesson in a few lines. Hope that helped. If not, you can ask more. I love the game myself. Also, if I was mistaken anywhere and someones knows better, please let me know so I can think straight too.