I would absolutely, heartily and without reservation recommend E.L.L.S.O. I usually suggest it to any late starter I come across , who is keen to make music with others. (No - I don't have shares in it
I went along one morning a few years ago and had an absolute ball. It was great fun and completely relaxed and unintimidating, but very productive.
My understanding is that it is run by the adult beginners for adult beginners. I believe they interview any prospective teachers to make sure they fit in with the organisation's ethos. i.e. No stroppiness/bullying/condescending attitudes, yet the teaching they get is highly professional. (There's also a break for a nice cup of tea).
Along with orchestra, there are group instrument classes and the opportunity for private lessons if wanted. (I think). They also run a Summer School each year which seems to well attended.
It's moved since I went along, but everyone was so easy going and happy to see a new face.
As for transport issues, I was stunned at how far some people actually travelled to get to it, so you might find a lift being freely offered. (Someone did when I went along).
I say, steel your nerves and get along there a.s.a.p. I bet you don't regret it. And if you don't no-one says you have to go again ever. (That's the joy of being a grown-up, playing with grown-ups
All the best
Iona