An excess of feeling produces teardrops. These are tears of emotion, but not the bad kind. You're just being moved to tears.

感涙 is an advanced word mainly used in writing. It refers to the kind of tears you might shed when you're profoundly touched with positive emotion, like when you're truly grateful for something or moved by a powerful speech.

This is a jukugo word that uses the on'yomi readings of the kanji. You haven't learned this reading for 涙 yet, so here's a mnemonic to help you:

Your excessive tears of emotion have ruined (るい) your life. Your friends didn't like being cried at for the smallest compliment or favor, so now they don't even return your calls. No one else you know is being moved to tears on a daily basis like this. It's ruining your life!