I feel like I'm just surviving and don't get a chance to live?

welcome to the club of surviving.

restore your health by eating healthily, e.g. some vegetables.
you will need to get involved in working to have a comfortable life.
the work you do should be suitable for your abilities.
most importantly, get a suitable job. It creates a sustainable future for you.
you need to work hard for what you want for - a comfortable life.
earn some money. you can only enjoy life after loads of hard work.
many good things/luxuries in life can be purchased with money, so just work hard in your job.
you will be rewarded at the end. If you don't want things to go down, you will need to work hard at your work to create a better life for yourself.

You sound like you might be overthinking things a bit. Just take a step back and breathe. Now, staying the same isn't always a bad thing. But, since you want to "Be in shape and grow as a person," I'd say that you try to find a bit of purpose and fun in life. A hobby. A friend. It could be anything. You need to find what defines you before you can find yourself and grow in yourself. I have books and an instrument (I play trumpet) to fall on when I'm feeling weird. I also confide in Jesus Christ. My life has been a bit bumpy, and once I found my Lord and Savior, I completely changed who I was. I have a completely different perspective and I'm so much happier. I would recommend Jesus as the number one thing for your case. I hope you get to feeling more positive, and I hope you learn to be happy again. **Internet hugs***

All this is happening because you are lacking action. You are the man behind the mirror, no one will increase your health or level of contentment with reality but YOU. What have you been doing to change things since you were 22? Action creates reaction. Lack of action will continue your pursuit "downhill" as you say. I think there is something on your mind holding you back. Only you know what it is, I'd say face it and crush all the limiting beliefs you've previously held about yourself. You are capable of many, many things. Leap and the net will appear. Don't focus on the past, just GO.

do you have a career with a steady income? if not, then you might want to take out loans for it. you can earn a degree online as well. you will have more free time and more money once you get a degree. maybe become a teacher? you help a lot and become a teacher is easy. but dealing with kids may not be. if you already have a career, then you should try to get a girl.