Stretching limitations

I have a long torso and short legs, and for the life of me I cannot get my butt to touch my heels (eg. in child's pose). I have been a fairly dedicated blender for 6+ years now and it's never changed. I also cannot pull my foot up high enough for a quad stretch, which i weirdly could before starting FB. I have to prop my foot on something, reach back and grab it.

Any ideas on what's going on? And how to make progress? Any and all feedback appreciated. Thanks Blenders.