Wanting to scale up in properties, but not sure how.

This is not a post on how to get started. I currently have 22 SfP and/ or owner Financed notes.  When I finish filling the last property I will be bumping close to 10k profit a month from them. ( after I pay off some credit card debt I used for my business) Since I have rolled most of my profit back into the business and doing rehabs etc I don’t have strong tax returns. I’m also self employed so most of my purchases have been with alternative financing without going thru the banks. I have been reading about the folks getting multiple units. I don’t have the reserves or the ability to get a loan based on tax returns. I think I would like to scale up in properties, but don’t see my way clear to do so. I’m not sure if I should just stick with what has worked thus far or scale into multi unites. If  I want to move up I’m at a lost of how to proceed.

Please advise.