You are not stupid. But you are still young and have a whole life ahead of you. Don't let it get destroyed by someone who isn't really there 100% for you.

Perhaps you might contemplate why you want to be in a relationship with someone who is so much older than you as well. Is he actually a "father figure" to you? Not uncommon at your age - but unlikely to work out well in the long run.

From what you've shared so far, it more sounds like he is in a mid-life crisis and gets a kick out of being with someone young. An ego-booster for him.

I suspect that your friends who are telling you that you are stupid are just trying to let you know that they care about you. Take time and reconnect with your friends and definitely take the art class. Become who you are - true love with the right person will come in time.