I am going to be a sophmore at my high school and last year I was the starting catcher on the JV baseball team. I am 6 foot 155 pounds. Really long legs. I got the perfect pushup at walmart and started doing those (about 100 a day) and started to see a physical improvement in my upperbody strength. However, my throwdowns to 2nd and overall my throws were getting weaker. My arm was feeling really heavy. But here's my dilemma. I know I need to lift weights for baseball, however, This next fall I will be playing on a 18u connie mack team that has recruited me and I don't want to show up there with terrible throws because then everybody will think that I suck and I have no margin for that at all.

So should I stop the weights now, or continue weights and have my throws suffer for a little bit?

You don't mention how often you play catch.

Also, you only mention your upper body. What are you doing for the lower body?

not sure why you are hurting from pushups(Ive done the perfect pushup and usually dont have any stiffness)

try jogging the day after,drinking lots and lots of water,and stretch your ENTIRE body after every workout.Not only will you help prevent injury but it could help take away that soreness you mentioned

i throw nearly every day of the week with my buddy. We're baseball freaks.

are you doing just pushups? make sure you stay balanced, for every set of pushups you need to do rows or some kind of exercise for your rear delt and back. dont start doing tons of pushups before you figure out a good BALANCED workout you could easily end up messing up your arm

You need more than pushups. Use compound movements, and along with your baseball skill routine, your performance will increase.