You sound very similar to myself. All the things you have mentioned I often feel. I was diagnosed a few years ago with general anxiety disorder (GAD)
I've always been a bit anxious/shy but it went completely off the scale when my Mum passed away suddenly. It was a very tramatic event and it's took me years to get better.
What worked for me was seeing a good CBT therapist for around 20 sessions. I was very lucky as she was amazing. She helped me get over all the odd scenarios I was thinking on a daily basis. After 2/3 years it creeped in again and I relapsed so went back into the mental health system. Thankfully it was with the same therapist again and I could just continue.
I find every few years it starts again and I just refer myself and wait for the appointment. My work is another option as I could go through occ health if needed. Antidepressants didn't work for me unfortunately.
The waiting times on the NHS are a long time unfortunately but I think you would benefit from a good run of sessions.
I still don't like it when:
the phone rings even if I know who is calling
I know a parcel is due, can't face opening the door
Making appointments
Driving to work every day in case I crash
DH late getting home - think something bad had happened
Worrying Ive left electric items on
Thinking I'll die suddenly like my mum.... Its so tiring at times.
When my mind starts thinking these things I read a script to myself of 'I am over thinking and being silly' my issue is I get over one worry then another random one will start. Its so frustrating!
But I am better than I used to be. Maybe doing a worry diary might help??
I know how horrible it feels, hope you can feel better soon