One more thing I might suggest is to start attending some of your town/city council meetings. You can also ask the clerk to put you on their mailing list for meeting minutes. Some have a sign up on their website. Just getting a feel for what your locality is dealing with can help you to understand what the local issues are. Local politics are often more accessible to change.
Pick an issue, or a few, you care about. Find the local or regional group that is already fighting for that issue. Join their newsletter. When they have events or meetings near you, go. Meet people and network. Someday you will find a way you can help in a way that fits your skill set, say yes.
It really is that easy to get involved, and these organizations need volunteers way more than they need money. People make the world move forward, not money, not votes. I mean voting and giving helps too, but giving your time is often way more important with activism.
Voting is a small part of political change, it needs to be done but that’s not where the work is. Getting involved in your community and pushing for changes is far more productive, activism of all types.
I would start by getting on mailing lists for things you care about and email for local city council meeting minutes. You might be surprised by some of the meeting times of local orgs. Some events are evening, but you can still learn about what is needed if you are staying engaged with local things. I can’t tell you what will work, but I reiterate I would start by getting on mailing lists for things you care about and take opportunities when they come.
Edit: and don’t be so hard on yourself, you can only do what you can do. Take your wins when they come and focus on those.