Yes, you have every reason to be sad (I'm going through the same thing), especially given how you would establish a connection with thoughtful gifts. Guilt implies that you're doing something wrong, which you're not. You're doing the right thing: the gift she wants from you is space and you're respecting it. The gift to yourself is pride and self-worth.
M39 D6 D3 (at S) S 2014-09 D 2016-09
"You can't start a fire sitting around, crying over a broken heart" - Bruce Springsteen.
