in need of advice

I love my boyfriend and I know he loves me, but I can't tell him certain things. When I first started our relationship, I was extremely insecure and my boyfriend would comfort and reassure me a lot. I'm still really insecure, but I don't want to tell him anything in case I scare him off. He acts loving all the same and is really goofy and funny, but I just REALLY need him at the moment.
He literally had to interigate my friends to find out that I was having suicidal thoughts and every time I talk about it, he changes the subject. The thing is we hardly see each other anymore because he hangs out with idiotic people who are the sort of people to make fun of me. He doesn't even stand up for me when I'm being insulted, even though I can handle myself.
I want to talk to him, but I barely see him through the day and I feel like he occasionally avoids me. I've talked to his best friend (my guy friend) and he says that I should talk to him, but I dont want to embarrass hi in front of the assholes he hangs out with. Please help xx