please help. :( How do I let him know I didn't mean this (short description, promise)?

My crush said his grandpa had cancer, so did my mom. I could never find a good time to talk to him about it so I left a note in his locker saying how my mom found a lot of natural stuff to help fight the cancer and that she'd be happy to talk to his parents or g'parents about it sometime and left her info at the bottom. Then on the back I told him if you ever need to vent somebody that gets it here's my info too and asked "what's your number so I can text you too?". It crossed my mind that he would take it wrong, but I ignored it. =( How do I let him know that I just want to be there for him? Giving him another note in his locker would be just.... I don't know. I just don't want to do that again, it's stupid.

Please help me out. :(