I keep getting back to where you said you like riding solo. If that's what you like, it seems that's what you should aim for. I don't know if that's a different type of cycling like gravel or trails, or lower traffic roads, or otherwise addressing your fears.
Personally i prefer riding solo or with one closely matched partner. I do what i can to mitigate risks, with visibility, road selection, and situational awareness, but i also accept the inevitable risks.