Gayle T,
You have already been given
excellent advice above and I agree with all of it: never chase, teach a "drop it" command, trade for something better, etc, etc.
One other thing that I would do is practice IGNORING pup when he picks up something that is yours. Right now, picking up something of yours is either 1) a fun game (mom chases me) or 2) a battle of wills (it's
mine now). Practice making it a total non-event. Make it boring for him. I'd do this by repeated "accidentally" dropping items of yours that you aren't worried he'll destroy - unimportant papers, old underwear, old socks, etc. When he picks them up, look at him, turn your back and don't say a word. In other words, don't reinforce the behavior with either positive OR negative responses. Later, when he's forgotten about it, you can quietly retrieve it. Repeat dozens of times per day.
Good luck!