Own 1 Single Family, how to lower monthly payments to lender?

[Humberto Campos]

Hi, 

I became the owner of my family's property, and got a loan as an investor, now I'm wondering how I can lower the monthly payment on the loan by a few hundred $ per month.

Some tenants struggle to pay rent on time and have gone MIA for weeks at a time, making me fill up the gaps. 

The several hundred $ I've had to cover concerns me long-term, so what would be the best way to lower the monthly payment, given that the current loan is valued at $300,000, and the equity in the property is $150,000? My current credit isn't great due to some unforeseen medical expenses, and my salaried income is $60,000 per year.

Thanks to all ahead of time!