Am I missing something here? If monthly rental costs are $5000 per month where you presently are, why would you sell your own place for 20-30 months rent. Surely renting your present place out will go a long way to subsidising your time in Thailand. Worth considering that Thailand isn't for everybody and if you still had your property back home then it's no big deal to return.
Did you originally open your bank account with one of the visas that they now require? A few things have changed recently. Some folks have had their accounts frozen.