all of sudden will not drive in any gear

So for some reason my vehicle all of sudden will not drive in any gear on it's own but reverse. Otherwise the only way it will go forward is if you enable "Winter Drive" , any ideas of what it could be? I have my beliefs that it may be a solenoid but i have also had people tell me that the solenoid is located in the transmission. so it would have to be taken apart and rebuilt. which i do't know if it's worth the money and hassle at that point. Any thoughts would be very appreciated.

Thank you!