It did seem like you had a rough week, but, I guess, that's life. Happiness and suffering are two sides of the same coin.

I wouldn't worry too much about erratic behavior unless you have previous experience with mania. However, certain medications are known to amplify specific traits. Just be aware, and if you feel that you are about to do something truly out of character, then talk to some one you trust before taking impulsive action.

That being said...

Savor your good moments! If you know a bad time is coming, no matter what you do, then... enjoy your happiness. You deserve it. You've earned it.

You said it yourself, there are people in your life that care about you. You might fall back into darkness, but there will be people surrounding you to cushion your crash. Try to put trust in that safety net of love and support.

BTW... I have to ask... Who performed at the concert?