Oh, can I relate! I get paranoid when the sun is low in the sky. You can use a white blinky. It should help, but ride like you're invisible anyway.
I was doored when I was 14 and that killed my desire to ride also for 20 years, so I do understand. A good book to read is "The Art of Urban Cycling", I think it's by Robert Hurst. It gave me a lot more confidence.
Do you have any bike paths around? That's a good option for the days when you feel freaked out. Or, ride when there's less traffic, early morning, or after morning rush hour.
I hope this helps.
'02 Eddy Merckx Fuga, Selle An Atomica
'85 Eddy Merckx Professional, Selle An Atomica
'10 Soma Double Cross DC, Selle An Atomica
Slacker on wheels.