Urgent help needed!

I have submitted an offer in mid May, but up to now, my agant told me that the bank approved, but we are still waiting for the final approval letter to come in.  I offered cash buy, but I have used the cash to buy other houses. So I do not have enough cash now.  Can I still back out?  My agent said if I back out, I will lose the $7000 deposit money, is that true?  Since I have not got the approval letter yet, I think I should be able to back out any time and get my money back, right?

Please help!  Thank you!