Can my lawyer withdraw in the middle of a divorce case without notice or warning to me whatsoever; provide me with no good reason; and keep retainer?

I'm in MI. I paid my divorce lawyer a special retainer of $7,500.00 which, as of Feb. 5 had only been billed in the amount of $2,000.00. On Feb. 5, my lawyer sent me a notice to withdraw and a subsequent hearing was held and withdrawal granted. This isn't over fees unpaid or bad ethics on my part. The only thing that could possibly be cited is that I had to move the mediation back a second time because I had trouble coming up with those fees. I paid for mediation days after my attorney withdrew. Now I cannot afford another attorney, my trust account that was being billed has been wiped out; my lawyer's office is uncommunicative; and I have no way of knowing what I was billed for. This in addition to being unprepared for mediation due to the sudden withdrawal and that going poorly for me due to no counsel.