As it turns out, I had to use a mod to destroy it. even stranger, after I accidentally did a full exit of the game and went back in, I was able to open the chest again on it's creator. I just wont use personal chests anymore though.

The mod I used was Infinity Hammer on the thunderstore.

Now if I could find out how to replace a few tar pits I mistakenly deleted XD

Thanks everyone for input on my chest problem!