I'm battling with myself to actually open up to my counselor and get help. Advice please?

I started going to a counselor a while ago because my mother found out that I cut myself. She knew that I have before, but I told her it was over with then started doing it in less noticable places. And recently, she also found out about my substance abuse because I got into trouble with the police, and I have to talk to my counselor (of course) about it. I like my counselor, but I don't exactly open up to her. I can't to anyone. I can talk to some people about some stuff, but I just can't actually go deep with people. I lied to my parents and I told them I was curious when they asked about the drugs, I said the same to my counselor and told her I enjoy the high and that's all. But drugs just make me feel 'right' I guess. And I absolutely hate myself because I keep telling everyone what they want to hear- I can't force myself to say the truth. I dont WANT help with quitting, and I honestly won't. I don't have a problem with that, I just don't know how to say it. I told everyone the self harm and substance abuse was over and done with, but I feel bad to be so selfish to them. My two bestfriends and boyfriend know that I probably won't quit, but they don't know why. They think the drugs are just for 'fun' but I don't know how to tell them its my life and without it I'm unbalanced. I'm worried this could ruin my relationship with my boyfriend, he means a lot to me, I know I hurt him and I dont want to. Me and my Mother think I may have Borderline personality disorder, but I don't know how I should talk to my counselor about that. I wish to be able to tell her ALL this, and perhaps my boyfriend. I do have the symptoms of BPD, but I don't have out bursts, when I get mad I act very cold, then I take it out on myself through cutting/drugs. Could someone please give me some tips on opening up to my counselor, preferably more about the BPD then the drugs, because I know that won't change, and I'm getting tired of sugarcoating it, but how should I say it?