It is understandable why you want to lower your monthly payments. With less than $2,000 a month coming in, it would be hard to make $1,500 mortgage payments.
Downsizing does sound like the right approach.
If you use the available income as suggested by the captain and multiple that monthly amount by 100, you will get a rough estimate of the loan amount you can take out on the purchase of a smaller home. You should add in about $45,000 net from the sale of your old home (if it sells for the value $230k) to see the maximum house you can buy.