The only thing I had for a really long time was my brothers old skateboard and still had all of his personal stuff on it and I would sometimes just sit with it on our sidewalk, still able to see him on it while he was supposed to be my babysitter. Distracted as hell trying to get that flip or jump. I know exactly how you feel with that shirt. Don't let anyone tell you it's weird or stupid. And don't lose that shirt for as long as possible because it's heartbreaking to lose something like that.
This doodle is beautiful and touching.
I love it

It's not stupid.

Everyone processes grief in different ways. Take your time do it how you need to do it. On the days when you need him a little more, do it.

As long as you aren't hurting yourself or others there is no wrong way to grieve.