Need Help With Platformer Slopes

Hello everyone.

I have a player object that is a square.
It can move left and right, collide with walls, and jump. However, I want to add slopes. Currently, my Slope Object's parent is obj_solid. I want to figure out how to make the following code make the player look for a slope that is no more than 4 pixels, and walk up it. If the code detects that the block colliding with the player is more than 4 pixels tall, it will collide with it like a regular wall and be unable to climb up it.

I've spent all of today and yesterday researching these forums and YouTube tutorials looking for a solution that isn't too complex. I'm looking for a solution that is basic as I am a beginner.

Here is my Horizontal Collision code:
// Horizontal Collision
if (place_meeting(x + hspd, y, obj_solid)) {
   while(!place_meeting(x + sign(hspd), y, obj_solid)) {
       x += sign(hspd);
   hspd = 0;
x += hspd;
Any ideas? I tried Shaun's YouTube tutorial, but if the slope was too steep, the player's speed would halt and then continue.

If you have any questions or ideas, please let me know.