It hits every nail on the head and I see it everyday where everyone acts like sheep and just follows the herd because some guru told them too.

Either1) your startup takes off and you can distribute profit fast enough to pay off your debts, or2) you find another source of $100,000 a year (which barely even starts to pay down the $300k, but might provide a better chance for a better loan), or3) you BK and possibly lose the rental houses to creditors (hopefully not, but we don’t know how they are held), or 4) you sell the houses, take the tax hit, work with the IRS on a payment plan whose interest will be much lower than your CCs, and focus on the startup.  

Just go through them, select the renovated/closely matching ones, and enter them into a model.Here's my fix & flip model, you can see the comps entered and some quick stats below them: Then I use that comp data to adjust the Sale Price in the model to what I estimate it will be (double check the resale $/sf is in-line with the comps), then adjust the purchase price until I hit my desired return level. 

From experience I can say that it is way harder, you have to find absolute home run deals instead of base hit deals and do often take on much higher risk. 

I have done a few development projects for myself and it seems that in every one you hit a bump and wonder why.  

Every hurdle hit it and solve it.9.  

In 1980 mortgage rates hit 17%.

The 4 real estate cylces have been hit.

Quote from @Mike H.: Its a tough one to really help someone with. 

But I hit a wall.First: Trying to find out what similar properties in the area (10 m radius) rent for, I used rentcast and rentometer for this, but they gave me two very different results.