Do I have to sign the substitution of attorney form received by my attorney?

No, you do not have to sign the substitution of attorney form which your attorney sent to you. If you don't sign, then the attorney will have to file a formal motion to be relieved as counsel of record. It will be up to the judge to decide whether withdrawing two months before trial is overly prejudicial to your case. Unless you really want to represent yourself in pro per (which is not recommended), you should probably immediately look for a new attorney to take over, and have the new attorney sign the substitution of attorney.

The attorneys motion to withdraw may cause a delay in having the matter resolved. Or, if the motion is denied, you will be going to trial with an attorney in whom you have no confidence (and who is not happy with you either.) You are far better off immediately finding a new attorney. wait to sign the form until you have a new attorney.

No. You do not have to sign the Substitution of Attorney but it may be in your best interest to do so. It appears that there has been a serious breakdown in communication between you and your attorney. An important part of the attorney-client relationship is trust. If you do not trust your attorneys advice or judgment regarding your matter than it is unlikely that you can move forward especially if you are unhappy with his or her services. You are much better off finding a new attorney to handle your matter if that is the case. As for the Motion to Withdraw, an attorney can file this motion to request that the Court allow him or her to withdraw from the case if there are sufficient grounds to do so. This of course will depend on what occurred between you and how close the trial is, if one is set. Your attorney will likely file this Motion if you do not sign the Substitution of Attorney.