As you appear to be off work at present, I imagine your GP will probably have given you one of the new Not Fit to work sick notes. If you were promised a certain level of mentoring and support and it hasn't been provided, I suggest you get in touch with your HR Department and ask to have a discussion with them to sit down and discuss what you feel you need to be able to return to work. . Who is causing the stress? Is it your immediate boss, or is the amount of work you have to undertake more than you can cope with? I think you need to be proactive in pursuing this issue if you want to try and resolve this problem. There wouldn't appear to be any grounds for your redunancy as presumably if you can't undertake the work, somebody else will have to be employed to do it. It sounds as if perhaps the job description was too demanding for your state of health and that your employers have been very patient allowing you to be off work for so long, and then allowing you to come back for a second chance. You do need to play a part in resolving this rather than just sitting at home hoping they will make you redundant.