How can I manage being the sole care-provider for my disabled child?

Join A Group. There are many support groups (both religious and non-religious) that deal with certain disabilities and how to cope with the associated stressors. Remember, there is strength in numbers. Also, your disabled child may find the interaction with others similar to himself/herself as inspiring and a welcome change from the day to day routine. Find joy and laughter in each day and renew your spirit.
Care taker. Being a sole care taker is a difficult task. Your should check with social service organizations for the services and help they can provide. Early intervention for the very young, special education services for older children, home health aides, support groups for parents with disabled children and day programs for older individuals. Reach out to family, friends and family members.