Please do not beat yourself up too badly, we all make mistakes starting out. I’m afraid that when I started my first saltwater tank I lost 4 clownfish to tail rot because I had no idea what to do for it. I also lost 4 anemones as they would stress themselves out trying to move because my light wasn’t strong enough for them. These things will happen, especially if we don’t have the right people to ask advice from. Please don’t give up.