Mental state after partial foot amputation horrible. Why should I go on?

Get some support. Depression is common after any amputation. Any loss of a body part can play a toll on a person’s mental state. Discuss it with your physician and join a support group, as you are not alone.
Depression? Amputation can be a life altering and difficult event. You should talk to your doctor about being evaluated for depression. You gotta look at life, and see that the glass is half full, not half empty. Just saw an olympic torch bearer in england, double amputee, running! lots of inspirational stories out there. You can be one too!
Support Group. Check with your local hospital or your local prosthetist for information on a support group for people like you. Believe it or not, there are many people out there who have been through the very same thing and they can help you understand and get through the changes.