{Game Maker} Slopes and Hanging from Ceiling Thread

Hello everyone, I'm working on a platform game in Game Maker were the player can hang from the ceiling exactly like in Contra 3. When I jump up and touch the ceiling I change States, and enter into a state were I stick to the ceiling. My problem is that I cannot make my character go up and down slopes while attached to the ceiling. I have tried many different scripts and techniques, but I'm at my wits end with this thing.

If anyone has any suggestions, online tutorials or examples of code they have used to solve a similar problem problem that would be great. Thanks you very much in advance, I really appreciate it.