Bad Deals Plus Personal Loans

[Account Closed]

I'll try to be as brief as possible. My business partner and I started a real estate investment business almost two years ago. We didn't want to use our own funds to invest so we used credit cards (10-15k) and a personal loan (45k) for down payments and repair/maintenance. 

Today we have two properties financed that are pretty bad. One is a duplex and one is a quad. We have two tenants in both. The two tenants in the duplex have been late on rent since we first purchased it (March 2019). There are two tenants in the quad. One has been good on paying rent the other has only paid rent one time since Oct 2019. Both of us are out of state investors. 

We have the quad on the market but it will only bring in 48k which is almost 20k less than what we purchased it for. The quad is pretty old and run down and ppl have broken into it a few times in less than a year. The neighborhood is pretty tough where the quad is located. What would you all suggest that we do? 

So far we feel our only two options are to walk away from everything and let our credit take the hit (rebuild it in the future) or throw more money into both properties and pay half and half on the personal loan (6 year term) and the credit cards or sell the quad and bring another 9k to the closing and keep the duplex for as long as we can and hope that the tenants pay their rent and that we don't have to make any serious repairs (already purchased a new furnace and had to pay for plumbing issues as well). 

Thanks for all the advice we can get!