dave, that's not always true. sometimes "you have to be" can be self-defined, as in "i have to be safe since i will attempt again...." and the hospital can be a place to stabilize a bit and let your meds kick in.
that said, the model here in ireland (similar to UK) is based on a community model, with psych services distributed to the community. i go to a day center where there are psychs, but also all sorts of out patient programs including group therapy, stress relief, art therapy, etc etc etc. the community nurses work from there but come out to your house to visit.
they far prefer outpatient here, and if you are feeling well enough this might be an option. there's not a day goes by i'm not either attending a program at the outpatient clinic, or on the phone with my nurse, or attending a relaxation class. it's not perfect (psych services ugh, don't get me going) but it's very thorough and i feel well-supported.
good luck with whatever choice you make, and please know you do have a choice.
c.