Unfortunately for your position, if you are past due, you have very little cover. If you have a payment agreement in writing from the landlord, that might help. But it sounds like that is not the case. As a result, you are behind and the landlord can demand that you catch up immediately or he can evict you. It is obvious that the realtor is pushing you to leave because the realtor wants his or her commission on the sale. It may be that your best bet is to talk to the landlord and work out a way to leave the property relatively promplty, possibly negotiating a release of liability for all past due rent and possibly getting some financial help to move so the landlord can close the sale sooner. If they go to evict you, they are weeks away from actually getting you out of the house legally, so you have a little bit of leverage, but not much.
This answer is for general purposes only, and it does not create an attorney-client relationship.