It's one of the major plot point. I don't remember the names of the skills but, there is one that makes him not level up fast and on that makes him get great amount of power. And the problem lies in the difference between his power and his body's tolerance due to his low level. Right now, his body is well and truly wrecked, so much so that the church lady had to use resurrection too keep him there.
From Rudeus we know that we need one girl to make one part of body to start moving again. How many girls we need to make entire MC's body to moving again?
Can someone remind me why his body is so fucked? Is it just pushing the limits all the time? Or is the Loner thing killing him per people in the vicinity?
Watch the sleeping girl-san say something like "huh? No your body is fully healed up, you just need to rest for your soul to settle after resurrection" or some crap like thst
Next chapter: Sleeping girl-san coincidentally found this one suspicious-looking ring and I scanned it with my skill and found out it can fix my wrecked body. Now I can recklessly do bs again.