there must be free services online for people in your situation. maybe even by skype or phone. Google?
continue to look for a purpose. if nothing else, make looking for a purpose your purpose.
idea...once you learn to overcome depressed/depressed feelings, you could share your tricks with others in a similar situation. Helping others escape from similar feelings is surely a valuable and noble purpose.
exercise! Outdoors if possible.
stay sober
volunteer at an animal shelter. or an animal preserve in a third-world country!
find a nice place to live. Something with at least of basic view of something green. Some place with a walkable neighborhood. Can't afford one in the US? Go to Urugauy and find one there.
if you have interet connection, learn new skills. then find better, higher-paying work, then move to a place you love.
go easy on yourself. we all make mistakes and go through rough patches. it's part of the human experience. make sure you cut yourself some slack for your mistakes.
volunteer at a place that actually NEEDS help. not doing your friend's errands. feed some sick people. help build a shelter for someone who's lost everything in a natural disaster.
do something of real value to a community in need: help exploited women/children. protect endangered wildlife.
go on a hike/camp in nature. BIG nature if possible.
enjoy good sex. it's one of life's greatest gifts.
if you use porn, stick to positive pornography and stick to a lower usage limit. excessive porn usage, especially of negative porn, can make one feel worse.
start small with successes: finish a word search. finish a lego set. build plastic models. learn to cook amazing deserts and then invite some people over to enjoy them with you. start small and gradually build up to more challenging achievements.
think outside the box: if you're already at the bottom professionally and working so much and you can't even afford a doctor, there's little risk in making a BIG move to another location (country?) or career.
what are you good at? which people NEED help with those skills? provide it. it will make you feel good.
practice appreciating all the little things. the flowers. the kids' laughter. the rain. music.
adopt a positive, gratitude encouraging mantra. one I use is ..."appreciate this, appreciate that, appreciate it all"
develop a marketable skill that you can do remotely. sure, work in an office if it's feasable, but also work in shared spaces, and also work from really nice locations every once in a while.
power is relative. move to a place where your current skillset is seen as powerful and desirable. being able to dig a well and install a pump might be really highly appreciated in certain parts of the world.
see this mood as something tht's temporary, like the weather. many great people in history have been very down and out before they made there mark on the world. you'll only know what you're fully capable of achieving in your life if you stick around and keep giving it your best.
be good to yourself, and then FELL GOOD ABOUT the fact that your a person that is good to yourself (see what I did there?)
be good to others, and then FELL GOOD ABOUT the fact that your a person that is good to others
be honest and try hard, and then FELL GOOD ABOUT the fact that your a person that is honest and tries hard
do those above three things and you'll be emotionally richer than most.
lastly... are there people out there that love you? Family? Friends? Those people will be emotionally devasted if you leave this planet prematuely. I guarantee it. So if nothing else, for THEIR SAKE, do everything you possibly can to live a long and content life. That means TRY EVERY LAST BIT OF ADVICE for finding meaning and contentment before you ever choose to throw in the towel.