Hey dude,
I want to address the comment you made, “I try to stay positive but it can be really hard to stop imagining how my life could have been, or how it ‘should’ be. People say your twenties are the best years of your life, but my 20′s have so far been spent struggling and ‘trying’ to enjoy life.” First, you need to eliminate the word try from your vocabulary. Try is an illusion. You’re either doing it or you’re not. There’s no in-between. Secondly, everyone’s life is differently. Think about it, what do the majority of people do in their 20’s anyways? Many spend it drinking, or going back and fourth between relationships, or even experimenting with things they’ve never tried before. That’s not my idea of the best years. Like you, I can’t stand alcohol, i’m too energetic for caffeine, and drugs aren’t something I’m okay with putting in my body. I too, have social anxiety and depression and have been dealing with them, without medication or therapy, my entire life.

I cannot say that I know exactly what you’re going through and nor will I. All I can tell you is that if you stop working, stop working on yourself, and keep focusing on negative things, you’re going to spiral further downward. If you know that this isn’t what you want, then you need to be the one to discipline yourself and pick yourself up. I know this is asking a lot, I’m aware that you may not know how, but I promise you, you absolutely can do this. You need to stop taking yourself and your thoughts so seriously. You get one life and you can either spend it miserably or happily. It’s actually funny how simple being happy is once you figure out how. It’s just a choice. Staying positive can be very difficult in the beginning, especially if you’re in the habit of thinking pessimistically but as you’ve probably figured out, it’s the hard things in life that benefit us the most. Hardships are meant to strengthen us, teach us, and give us the opportunity to grow physically and mentally. You need to see how you’re perceiving your current situation. Yes, it may be hard but you’re going to overcome it.

“Who you are today is who you were yesterday and who you will become is who you are today.”

This is just an opportunity for you to become the person you want to be. It’s going to take a lot but if you stay true, you’ll be the person you want to be. Only when you shut off your negative mindset can you become that person though. I could write a hundred pages about this but in all honesty dude, you just need to get started. Find motivation in knowing where your current choices are leading you and find motivation in becoming the man you want to be. Get a job, start exercising, get out and make it your priority to teach yourself to block out the negativity. You must begin with action. Stop accepting your depression as a reason not to do something. Stop allowing your anxiety to dictate how you interact with the world around you. Open yourself to this life you were blessed with and spend every moment you can sharing that joy with your surroundings. As someone who has been down a similar path, to do nothing and give in is the beginning of the end. Don’t ever think that you don’t deserve happiness. You do. Keep seeking help, keep refusing to give in to the suffering, and witness the man you’ll become.

“Knowing is not enough, we must apply. Willing is not enough, we must do.”

I hope this helps.
I have a personal blog that you might benefit from. It’s thepathofaronin.blogspot.com
Let me know if I can help or if you have any specific questions.