I agree with Christopher, a Realtor can help you find a tenant while still have your house listed for sale.
I don't believe they will try to just sell - because if you can't afford to sell the house, you'd either take it off the market; nor move or short sell it. So, it'd better for the Realtor to help you rent it out while still listed for sale; it will be easier to monitor the situation - add bonus is that you will like their service and will continue to use them when you eventually sell the property.
I don't know how close you are to your property. If not too far, you can do property management yourself which might be easier. Otherwise, you can hire a property management company to do that but a lot won't do short term.
Your Realtor might not be able to help you manage the proerty - I can't. First I don't have formal training, and second, my professional insurance only covers buy and sell real estate not property management. I suspect a lot will be in the same boat.
I did help a client once, pro bono, but I also have them sign something to say that I am not responsible for anything. It worked fine!