1- Have you run the numbers for a cash out refinance, using current comps as you describe? If you can get a HELOC, you might be able to cash out. No ongoing interest payments with cash-out; just a one time transaction bite (closing costs), plus the mortgage you were already paying.
2- In terms of risk, advice to a conservative landlord would be to build your emergency fund cash reserves first (personal + duplex), and then build some funds to buy another property.
3- I tend to agree with some of the BP podcast guests: Flipping is the easiest way to generate cash, when you're young and cash-poor. Get good comps for ARV, get multiple repair estimates/bids from GCs, and use a hard money lender who will lend 90% LTV + 100% rehab. Go slow for your first, ask BP community for help, look around for area wholesalers who specialize in finding properties in need of rehabbing. And never ever buy if the numbers don't work; leave emotion at the sports stadium :)
Once you have sufficient cash, you can get the BRRRR train rolling and cycle that cash in & out of buy-and-hold properties and refinancing.