How do i prevent my elbow pain in throwing baseball?

It depends: In a younger person, this could little league elbow and backdown of the elbow joint that can lead to long term elbow problems. If the pain is medial and goes into your ring and little finger, it's probably cubital tunnel syndrome, which is a pinched nerve on the inside of the elbow. If its the outside of the elbow, it may be tennis elbow syndrome. If it keeps hurting see a doctor.

Shoulder strength!: Often times in overhead athletes there is a major biomechanical abnormality in the shoulder that effectively puts strain on the elbow and may lead to pain or even further injury. Addressing the shoulder with specific exercises for the rotator cuff and scapula can help with biomechanics. I suggest you see a sports medicine physician with experience in shoulder and elbow injuries to fix this.

Minimize the amount: Of curve balls you're throwing. That's it.