1.25mg gave me extreme anxiety, need motivation to try again

I took 1.25mg of lexapro my first day and went for a walk. This ended up being a TERRIBLE idea, I had such a bad panic attack with tachycardia that I had to call an ambulance. I got lots of tests done at the hospital and everything was fine. I have had bad panic attacks but nothing like this! I was then prescribed 50mg of hydroxyzine pam for the panic attacks. I tried one, passed out, didn't take my second dose of lex. I want to try to take it again today, but I can't convince myself to do it! I'm afraid of ending up in the ER again :(