I'm genuinely sorry for what you're going through.
You didn't ask for it but I have some advice.
First, don't let them claim real estate in your head. Don't read their FB posts and, when confronted with their bullshit, practice a bit of zen "letting it flow through you". You know it's bullshit, we know it's bullshit. Don't let the bullshit stay with you.
Second, don't pick their bullshit ideology as the ground on which you relate to them. As I've said in other posts, sports and cooking (two of my own affections) were invented so that we don't have to talk about politics. What if THEY start on politics? That's where you learn the art of aggressive changing the subject.
"Trump was cheated out of the election by the godless Democrats."
"How do you think the Broncos will do on Sunday?"
"The last batch of chocolate chip cookies I made just melted and ran all over. Wonder what I did wrong."
In other words, don't feed the trolls.
As to your Toastmaster group, DON'T give up on something that has brought you joy in the past. When some dumb shit fascist gives his/her talk on gun rights, make your next speech about the Tulsa Massacre. When another dumb ass crypto-Nazi gives an anti-CRT speech, make your next one about the fight for worker rights in West Virginia back in the 1920's.
Third, when something they say or do manages to upset you, turn it into activism. Call a legislator. Write a letter to the editor. Subscribe to another liberal magazine. Donate $5 to a liberal candidate. As you say, nothing you say or do will change their minds so support the people and institutions who are already on your side.
Lastly, when the assholes get you down, do what you did with this post...look for support from like minded people.
You and we are fighting the good fight. We can't buckle under to the shit heads and racists.