By all means add bacteria. Also, see if you can get some cycled media from your lfs. Get a test kit that tests for ammonia, nitrites, and nitrates. Test every day before your water changes. You should gradually see ammonia and nitrite levels decrease, then nitrate levels increase. Continue with daily water changes until ammonia and nitrites are zero. Add water conditioner with each water change. I went through same thing. Gotta do daily changes if you want to keep your fish.