How to avoid running out of money?

[Peter Hanson]

found a rental for $125K that rents for $900/month, bought it with 20% down payment 4 months ago, value has gone up to $170K

found a rental for $90K that rents for $800/month, bought it with 20% down payment 3 months ago, value has gone up to $135K

found a rental for 108K that rents for $850/month, bought with 20% down payment 3 months ago, value has gone up to $130K

found a rental for $150K that rents for $1800/month, in escrow right now, plan on putting down 20%, fixing for $5000 and selling for $180K

found a fixer/REO for $75K plan on fixing for $10K and selling for 110K, in escrow now going to pay cash and plan to resell in 6-8 weeks

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Short sales waiting for bank approval:

4/2 SFR for $105K needs $12K in repairs, will sell for $160K

4/2 SFR for $440K needs $15K in repairs, will sell for $600K

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Moral of the story I can find decent priced flips/rentals but I keep running out of money. What is my next step in this business? I can sell some of my stuff, but I'd like keep it because I know a year or two from now it's going to be worth much more than it is now. How do I balance between flipping and keeping? what would the more experienced guys do? Ideally buy, fix, rent, refi the cash back out, and keep as a rental forever?

Sorry for rambling...any help would be great

Pete