How to lower my Mortgage payment

you can begin increasing the payments each month (there is no  permission from the servicer required to do so) so that the extra payments go towards principle and ultimately the mortgage pays off quicker.   Even paying an extra $100 per month eventually ends the mortgage earlier.  there are plenty of mortgage calculators on the internet where you can figure out the impact of increasing the monthly payments.

The further benefit of increasing the monthly payments is that if you find yourself challenged in a  few years to maintain those extra payments, you can simply stop.