dont quit buddy , just take a breath and listen to me, your doing to much , think about it you noticed a small problem that wasnt a problem , you rectified the problem(which doesnt exist) since there was no problem now youve upset the balance of your already fragile system my advice do your water changes and relax. losing a few corals in your first setup is nothing alot of us including myself have lost full systems the trick is knowing that success isnt easy and expecting the worst before it happens is being prepared:P
biggest and hardest lesson is keep it simple in your case right now its water changes and get things back to routine, consistency and maturity are the key.
if i were you i would do some water changes add nothing and monitor..... after stability comes back i would look into gettng some birdsnest or pocci as my first sps frag
cheers buddy and good luck any questions just shoot i would be glad to help any way
stop buying beginner frags at lfs those should be free from reefers then once you know you can do it go buy the stuff you want to have