Moving from a SF to a MF?

[Michael Webster]

Hey everyone, I bought my first house hack when I was 25, and have lived in the same place for the last 9 years.  I've always rented rooms, and have gotten into AirBnB big time in the last 2 years.  Last year I was able to make a pretty solid income for my area, and I'm ready to move onto a multi-family property so I can rent out my house on AirBnB for the Summer.  The problem is, no banks are convinced that I'll actually do it.  They all want 20% down + as an investment home, even though I've tried to explain how hugely beneficial it would be for me to move out.  Any thoughts on how to get around this?  I would hate to sell my house as it makes me about 25K in profit while I'm living there and would make me even more if I moved out!  

I do have 100K in equity, but I'd prefer to not open a credit line to have the larger down payment, but maybe it's worth it.  Any creative ideas, suggestions, are much appreciated!  If you need more info let me know. :)