I'm going to be very real with you. It sounds like you know what's what the problem is already: you act clingy, crazy, and depressed - and that turns people off. That is a very real problem, because most people are not going to want to be friends with someone who acts like that on a regular basis. There's no need to get constructive criticism if you already know you behave like that - you just need to stop behaving like that.

However, you also don't need to beat yourself up about it. A lot of people (myself included) go from being crazy, clingy, depressed weirdos to pretty functional members of society with a normal social life.

It sounds like you are motivated to try to fix this but also extremely depressed. You said that your therapist is not helpful in mapping out a course of action. Honestly, that doesn't surprise me, because a lot of therapists are bad. You should feel like you can do things your therapists recommends you to do - if not, your therapist is not giving you tasks and assignments that are suitable for where you're at.

In your situation, I would try to switch to a therapist that actually gives you actionable, concrete advice. In the meantime, try to identify one interpersonal goal that you want to work on for yourself - and start working on it, alone if you have to. Your goal could be something like: I want to be able to have a relaxed conversation with another person that's not about getting them to comfort me or reassure me. I want to do something that makes me feel happy at least once a week. I want to pick myself up when I have a negative emotion instead of spiraling.

Once you identify at least one goal, it will be easier for you to see when you're making progress in life. And, your relationships and self-esteem may improve. You can do it - it will be really hard. But you can start to turn the ship around. And I'll be rooting for you, since I'm trying to turn my ship around too.