If you're just way over the edge, you might have to just cut your losses. 

Even though my loss was small, it was a good learning experience and I will need to meet with private investors in person before it can be considered if we both will be a right fit. 

Not to throw shade on what you're doing, but you can buy a duplex,....move in ready probably in Cleveland (like I do now), Columbus, Philly, Memphis or KC that already has tenants in it for $85,000 and has gross rents of $1,200 to $2,200 in a decent neighborhood.I'm not an agent but probably plenty here on BP that can help you out with that.

Here is a great link from the NDSU Extension office:"A simple way homeowners can check their homes for heat loss is with an infrared thermometer.

The only exception is emergency service requiring entry to secure loss of life or property.

I think some people have touched on it but;Does it make sense to sell at a small loss or spend money on a renovation? 

Assuming you could carry the payments in the case of a loss of a tenant, at least with the least option ... you can just keep collecting NROC while you pay down your seller financed mortgage.

Much of that was the surprises,  but a portion was the extra time and effort it took to figure out some of the new things were were undertaking (like the floating subfloor).The more painful bit was the length of time the unit was off-line - almost 6-months and the loss of revenue that goes along with that.  

I am just at loss on figuring out how to put all the pieces together.

I think when I was in my 20s, there was a certain reckless abandon that helped me win big on certain deals (deals that I wouldn't do now that i am older and more cautious) and taken on big losses.