The first order of business is to quit exhausting yourself. Don’t waste time on people who aren’t going to listen — who are literally being paid not to listen. Above all, this means abandoning the Democratic Party as a top-down institution and its current funding model. There is no chance of reviving the New Deal commitment to working Americans within the context of perceived centrist politics. Neither Roosevelt is coming back; not FDR for the Dems nor TR for the Repubs.
What you can do is field alternative candidates to mainline Dems in the primaries. This takes discipline, time, and a willingness to fail over and over until you succeed. This is the shit you do have time for, that you damn well better make time for.
There are issues you can win at the local level. Medicare for all, debt relief for students, basic income guarantee, a foreign policy of non-interference. People will listen and respect you if you espouse what is right.