- The pain in the shoulders might indicate that you either have a technical or physical issue. It could be that you lack shoulder mobility, specifically external rotation (tight internal rotators) and receiving the weights in what constitutes for YOUR body an excessive range of motion puts strain on your structures.
OR it could be that you are doing a "pull and pray" (especially in the snatch) which is essentially exploding upwards, almost throwing the barbell in the air and then the bar "falls down" without you controlling it until it hits the catch position at which point the shoulder muscles contract to the hold the bar. That does put a lot of stress on the shoulders. In reality you should never stop interacting with the barbell. Pull the bar up and when you go under you immediately switch to "pressing up" into the barbell, imagine trying to lock your elbows before your feet move into the catch position, that way it's your whole body that absorbs the shock.
I made this video a while ago for someone who posted a video for analysis, not necessarily 100% applicable to you, but some of it might help.
- From experience the Olympic lifts can develop some shoulder mass initially, but I wouldn't count on them to put on a lot of mass there. Weightlifters rely on various presses to build upper body muscles, not the lifts themselves.