Social security will count as monthly income and can be added along with any additional monthly income. As far as the life insurance, it will be counted as cash on hand but not monthly income unless it is coming to you in scheduled payments. Please contact me and I would be more then happy to provide you with a list of local mortgage professionals in the area.
You will need proof of the social security payment from Social Security and if you are receiving the life insurance in monthly payment it can be. You have to prove both will continue for 3 years. If the life insurance was paid in a lump sum you can use it as down payment. In that case I would encourage you to talk with a lender and way your options on what type of loan program would be the best to fit your needs.