Your investment property - This you could do a 1031 exchange on and buy another property you intend to use for investment. 

Quote from @Patrick Roberts: Angel oak and A&D mortgage are two of the bigger lenders that I know of who will do 2nd's on investment properties as of a few months ago.

Wrong Property Management ApproachIt doesn’t matter how good the people who are doing the property management are, if they are not using a property management approach designed for co-living, everyone loses.  

If you're willing and able, I do recommend the "house hacking" strategy which is just a fancy name for buying a rental property and living in one of the units, because you'll get very favorable financing - an owner-occupied fixed-rate 30-year mortgage.I'd also say, analyze that property as if you won't live there and it's a pure rental, and make sure the property is still cash flow positive if there's a tenant in your unit because then you'll know if it's actually a good investment.And when you analyze it, include payment of a property manager in your #s because if you don't, and doing so would make it go cash flow negative, then you've just bought yourself a job because you literally can't step away from managing it without losing money.

@Cole Starin sometimes it makes sense to sell the WORST property in your portfolio.Another option is why do a LOC on the duplex, when you could just do a $100k cashout refi to pay off all your debt AND keep the property?

At the time QB was not the best for property management.

Looks like you made a good decision with property management.

My first thing is to start built relationships with realtors and property managers.

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Get a job in property management.