Sell, refi or HELOC to tap equity? Advice for next step?

[Matt Said]

I'm stuck in a little analysis paralysis here and would love some feedback. I have a 4 unit in Chicago that is barely Cash Flow positive because I keep one of the units for myself but barely use it since I spend 99% of my time in the burbs. I'd like to leverage the equity but I'm conflicted on whether I should: sell, take a HELOC or refinance to free up some cash for another Multi Family, maybe commercial bldg. Or keep the 1st property and use as collateral for a 2nd bigger property if I can find a bank who will work with me.

Making up the numbers for simplicity sake but paid $350k, put down 20%/$70K and it is worth about $450 today.  I owe $230k on a 30yr fixed at 3.5% with about 23 years left to go.

My concerns are: losing a great rate and paying taxes/commission on a large chunk of the equity.  Upside: more units, potential good cashflow, etc.

My overall RE goals are wealth generation (retire early) with cash flow second (but always appreciated).  I have

Any thoughts would be greatly appreciated!