Hey- I know how you feel. It's completely understandable that you would not feel grateful for these gifts but since you're not out, you owe it to the givers to put up a front for them (or come out if that's an option, I suppose.)
Pre-T I didn't want to be anywhere near that kind of stuff even though a couple years ago I used to wear a lot of jewelry etc. After a little while passing/presenting as male it started to bother me less and I still have the same tastes as I used to have. Maybe you will want to keep a few things, like the bracelet, in case you like it later. If you're straight, hey, you can give it to a girl sometime. XD Just keep the things that you think are nice and discreetly rid yourself of the other things. Or hide them/whatever.
I think the box is a good idea. No reason to waste good things and I'd say at that point in your transition, you are not the same person you will be later. You can decide then when you don't feel so emotional about it all. Sometimes it's nice to look back anyway, imo. But you know, this is just me and I don't really know how you are. You might want to burn everything and I think that's okay, too. Your choice to make etc etc.
Overall I just want to say don't feel guilty about this! You can't decide how you will feel about things and your feelings are as real as anyone else's and your reasons are, too.
I hope I helped somehow.