Are you getting help from a professional, therapist, Primary Care Provider, or Psychiatrist? If not, find one. They can help. I was where you are and now I feel better. Ask them to recommend a group. You can go be around people who understand that you’re depressed and want to help, until you don’t feel like isolation is necessary.
This is completely anecdotal and kind of besides the point. The two things that were most helpful to me, in the long term, were magnesium supplements and a gratitude journal. Magnesium has helped straighten out a lot of my anxiety and sleeping issues. Writing down five things everyday has really helped put things in perspective. I now realize how many of the things going on around me are magic. Lights in your house, massive grocery stores full of food, hot water that comes out of the tap, airplanes and cars, the internet, cellphones, most of the world’s knowledge in your pocket. It started to wear new paths in my brain. Seriously, six or eight weeks of this and my perspective changed. The world is full of really amazing, really awesome shit.
It sounds like you may be spending a lot of time on social media, where unproductive inflammatory messages run on a loop, wearing the wrong kind of tracks in your brain. Try an experiment, find a non-political hobby and stick to forums about that instead of news and politics for a while and see if that helps. Try two weeks without Facebook and Twitter.
If you’re really worried the world is only getting worse, read Stephen Pinker’s “The Better Angels of Our Nature”. He argues, pretty convincingly that we are living in the safest time in history and the trend is towards more safety and less dog eat dog.
I empathize with your desire for community and perspective regarding its decay. While we don’t have as much default real life community as we used to, it does still exist. I don’t know what you’re interested in or what your geography is but there are still groups of like minded people who get together to do like minded stuff. There are knitting circles, hackathons, bowling leagues, Boy Scouts, meetups, meditation circles, church, game nights, pub quiz, BINGO with the Eagles, Ultimate leagues, book clubs, support groups, walking clubs, and 100s of others all going on now. It takes a little more work to find them, but these communities are usually very welcoming.