Hi, I'm new here so bear with me.

I'm in a house that's 5 1/2 years old and we are the original owners. Our back exterior door is difficult to open and shut due to the fact that it seems to be hung crooked. I can look at the bottom of the door and see light from the bottom left corner just about all of the time. It seems to be very drafty too. I recently replaced the brick moulding around the door and we didn't notice any problems with the jamb at the time as far as something that would need repairs but I've noticed that this issue is becoming worse each year. I'm sitting here looking at the door now and it looks like the frame itself could be warped or something like that. I know that the house will settle over time but this is just about crazy. I feel like I'm losing money each time the HVAC turns on since I'm pretty sure there's a significant leak on that door. I'm planning on replacing the weatherstripping today as well as adding a door sweep, as a temporary solution. Is there anything else I can do, or should I contact a contractor to come out and replace the whole thing?

Thanks