I see that you are hurt by his lack of attention... but trying to get back by doing thing to hurt him does not help the situation. If he is depressed things like taking the ring back only will push him farther away.

If you are done with him, then just end it and move on. If you want the relationship then work on it, and help him through his darkness...

My ex fiance gave me the ring back (supposedly as a joke... long story) but that hurt even worse than her cheating on me which is what ended the relationship.

I wish you the best, and hope that you get what *you* want and need.