You can claim attorney fees when you're indigent and the other side has the ability to pay, but you have to ask for it when you're pursuing the action. In other words, if you'd asked for fees when your custody case was being heard, you'd have had a chance to have your ex pay for it. But you didn't ask for it, or make your attorney aware of your ability to pay (or lack thereof). So instead you agreed to pay your attorney. Now your attorney has an agreement (fee agreement) that you performed - partly. The other part of your question - what's the statute of limitations on attorney fees - may be governed by state law, so I'd go looking for state law on the subject.
Is this “helpful” or a “best” answer? Please mark it if it was, and I hope it was! Thank you! Nancy L. Ballast is an attorney in west Michigan, with a practice centered on family law, estate planning, and criminal law. www.nancyballastlaw.com