Help!

I’m so sorry, this has had it; it’s not up to being worn or washed any more.

The only thing I can think of is to use a whole new shirt as a lining, stitching them together all over to distribute the stress, and even then the old shirt is likely to continue shredding.

Even repurposing it as (eg) a pillow cover it won’t last.

If it’s very special to you you could frame it? 

If you love the design, you could add it to another shirt/sweatshirt! I just did that for my SIL. I added heat&bond to help stabilize, cut the design and then applied it to a sweatshirt. She wears it all the time!

I think I’d give it a go with sashiko mending using a thin cotton and maybe an elastic thread(?) If the repairs aren’t in an area that gets stretched when you put it on, you might be able to use regular thread. Then I would wash it in one of those ‘delicates’ netted bags for the rest of it’s life.

I have no idea about saving the structure, but you gotta add some 3D crewel foliage. DO IT DO IT

It's a very cool shirt- it'd be a shame if you can't do something with it. Those holes are odd- I wonder if it's had bleach or something corrosive splashed on it that's weakened the fibres and the wash has just shown that damage?

Assuming the damage is localised and not all over... I would go with patching or applique. Sashiko style reinforcement might work. Then, you could maybe add some embroidery here and there to blend the mending a little. Either way, I'm not sure I'd trust the non-damaged areas with any type of darning or stitching. Would be good to see what you come up with!