How to be less emotionally clingy to my best friend?

I am independent in the sense that I can go out and get a job on my own, learn new skills like biking, book and arrange my own appointments, go out in public by myself, ETC. but when when it comes to my friends I immediately attach myself to them. I have trust issues and have been scrutinized and criticized by people my whole life.. I'm 18. I am going to see my BF this week for dinner and hes starting to pick up on my anxiety/depression and I hate it! What can I talk about with him/try to think about so I don't come across a big emotional mess who constantly needs validation?