Hang in there mom. *hug* all sucky but you got this! I had tons of nose bleeds as a kid with the changing seasons. When you said turning on a faucet, yep I know that one. I remember sitting over the bathtub because it would be so epic it was the only way not to make a mess. You've already heard some good advice so I won't repeat it.
As for the heart murmur, something to watch but it really is probably nothing. Common in youngins as their hearts are still developing. (Stupid grin on face as I am learning this in school right now).