@Mariangela CiciarelliHey Mariangela, I HIGHLY recommend you connect with @Josh Green.

If it does, the interest rate doesn't matter as it is just a part of the calculation.You might also look at selling one or both of the properties in a 1031 exchange and buying into a new property (or several) that provides higher returns. 

Talk to some “high end” realtors and see if they have opinions?

(You don’t care if apartment rents are going up or down if you’re renting SFR.)So you’ll need to find a source for historical rents for SFR in the city or preferably zip code your property is in. 

Any advice from the rise minds here are greatly appreciated

Highly leveraged, minimal cash flow as is, little cash reserves and yet you probably want your property to appreciate but don't want the tax & insurance to go up.

These days with high rates, I can see it being very difficult to find a property that would work.I second what Stevo said, huge difference between 4plex (residential financing) and 6plex (commercial financing).

If I had time to take a 2 week course on it to figure it out, maybe I would have felt differently, but I'm looking for uncomplicated and if their stupid webmaster can't come off his high horse and make it easy then I'm not paying $50 a month plus the lead generation costs...and thats my 2¢

Knowing that market rates are in the high 6s at best, and much higher most likely, I would be looking for at least 6% interest. 

One popular way it’s adding an ADU to the property and renting that property as a tiny house or studio apartment.4.