You can retract the offer it it has not been accepted.
.
just had to repeat that.
Get on the phone NOW and contact your agent. If the offer has not been delivered, tell the agent to not present it. If it has been presented, as long as it has not been accepted, you have the right to rescind the offer. Tell your agent to get on the phone and rescind the offer NOW.
keep track of the time of your phone call. It could be critical.
If you wait and the offer is accepted, you then are basically stuck with it. There are other ways out if there are contingencies but why mess with that if you don't have to.