I feel lonely

I have a lot of people who care about me in my life but i feel lonely, i cant talk to anyone about my problems, i've tried going to therapy three times but i just cant manage to open up to anyone, the only two times i managed to open up to someone it was to my mom and my bsf, both didn't help at all, they just made me feel even more misunderstood. I don't even know why i cant open up, i just cant, and it's driving me insane. I had only 2 friends in middle school but this year i met a lot of new people, i've always felt lonely but never this much, i think mostly because even if i have a lot more friends now, none of them really cares about me.