Quote - > Quote - even though i have already been playing for 2 years, many times i get sudden aweful pains in the fingertips and it stings so bad.

If it hurts is because you are doing something wrong, too much pressure, wrong fingers position, wrong guitar, wrong string gauge.
Learn some techniques and find one and also an instrument that fits better your hands.

Even when you're doing everything right it hurts, let me clue you. When you are first learning, or don't play very often, the strings hurt. (has played guitar). The only way to keep it from hurting is to make the skin thicker. And the only way to do that is play. Don't matter what gauge the strings are or any of that. It's gonna hurt at first.

Laurie