I know it may be difficult for you to believe at the moment but you're worth far more than you realise.
I'm wondering if you ever over analyse or criticise what you do or say when you're your most natural self (without the drugs and alcohol). Do you feel like what you have to say is worth saying, until you come to analyse it later? Is it possible that it is actually worth saying but you're saying it to the wrong people. If you were surrounded by people who could relate and enjoy the conversation, would that make some difference to you? Do you feel like you would be worth more, not worth less around people who encouraged you to be your natural self? What if you found people who were in a similar situation to you in life, would you be feeling differently? Would you feel more understood and supported? Would you begin to feel like you were worth more, as opposed to being worth less that others?
Is it possible that you're discovering a kind of emptiness in the way of what your friends and family have to offer you? Is the emptiness outside of you, not inside? Would life feel fulfilling if you found your self among people who naturally fulfilled each other in positive constructive ways? Can you imagine the sort of people who naturally raised each other through challenges and the way of personal evolution?
While your friends may appear to be accomplishing great things, you are accomplishing one of the greatest things a person can rise to - self questioning. By the way, if a person in a mid life crisis begins questioning earlier in life, chances are they won't hit the mid life (identity) crisis with such intensity. They will have come to understand the importance of questioning their sense of self. This is how we graduate through life. Some graduation challenges prove to be far greater than others. No doubt about it!
So, the question is 'Do you know who you want to become?' Another question, 'Do you know the kind of tribe you want to begin vibing with, at a deeper more fulfilling level?' Does your graduation challenge involve some serious form of personal reformation?
Remember, never stop questioning. It's the way to greater consciousness on the path of personal evolution.
Every time we evolve or reform our self, we come to realise (at each new stage) that we are worth far more than what we believed our self to be. We are not worthless.