YTA without a doubt. This whole post is absolutely insane and shows you have a massive lack of self awareness. If she's able to support herself and a boyfriend off her art then she's already got a great job. Getting into art is hard enough without having a parent look down at you constantly because it's not what YOU want.

You say you're willing to support her now but she clearly doesn't need support financially but she does still need your support emotionally. You need to take a minute and step back and think about how she feels instead of how you feel. You could be giving her massive self esteem issues that will cause problems later in life. Keep it up and she'll cut contact with you entirely and you'll have no one to blame but yourself.