You should visit the Job Centre and talk to your advisor. They will have advice about the sort of work you can apply for and the expectations you should have. There may also be incapacity benefit that you can claim??
In the meantime look for the sorts of jobs which don’t involve lots of manual labour and start applying. The sooner you get into jobseeking, the better!
It would also be wise to talk to your doctor and maybe get a referral to a physiotherapist. They will be able to give you exercises to strengthen your back muscles.