Perhaps consider renting your current home out. Or offering it on a lease-option basis to a tenant-buyer. The latter will produce a bit more in monthly income, and might result in an ultimate sale at a break-even price.
You have a lot to put down, considering your planned purchase price . . . if you can find a property for $40,000 or so. And that raises another question: Would you be able to find financing in any case on the new property? That loan amount ($20,000) is below the threshhold that most lenders will consider lending. So you might well be looking at owner financing on your new property. Nothing wrong with that; in fact, that can work to your advantage.
However, I wouldn't advise you to buy (or commit yourself to buy) a new place until you absolutely know what you'll be doing with your current home. So, really, that means having a Realtor do a CMA on your current property (to know what it's likely to sell for) and having the Realtor tell you what your present home could rent for, and talking to a lender (to find out whether you could even borrow the money you'd need for the new property, or whether owner financing is your best option).
Hope that helps.