My husband died suddenly just over 2 months ago - I too weep all over the place, on train platforms, at work, in shops...grief is just so overwhelming. Loneliness is inevitable, but I think it does make it worse if you have no-one to talk to. Even if you are going to move back to the UK, it might be worth talking to your doctor in France. I live in Belgium and I’m seeing a grief therapist here, which does help. I know language might be a problem, but you may be able to find one who speaks English. Could you maybe try skyping with friends and family in the UK? At least that would ensure that you have someone to talk to every day. I really feel for you - and you’re right, no-one understands until they go through it themselves. Try to be kind to yourself and give yourself some time to rest and grieve too. I can’t say that as the months pass it gets easier, but you do start to learn ways to deal with all that pain, even if it does continue to hit you in waves at unexpected moments. I’m sending you a big hug.
Charlotte