As your daily routine has changed  and most of the time you dont have any work. So it cause you feeling of boredom which itself cause u stress. Initially its difficult to overcome all these but with time you can get adjusted . For that involve youself in other activities and in your hobby. Join some senior citizen group in your nearby area. Watch TV , read newspaper , magazines , and if possible join any part time job even on less salary. You can also do charity work by attaching youself with any NGO. Try to provide benefit of your experience to coming generation. At home spend quality time with your wife , children and specially with you grandchildren. Meanwhile you can also plan vacation trip with your family or spouse.