I agree with keeping a few things for sentimental purposes, but I also agree with Steve that stuff is stuff and all replaceable. It doesn't have to mean anything. It feels a little similar to the piano question (that was you, right?)
My guess is that it feels like pressure to him, that staying in the R with you means capitulating to having more children. It is no skin off your back to donate the clothes and supplies, or sell them and buy something new for the baby with the $$. Someone else can get a lot of use out of them when they'd otherwise be sitting in your basement, silently pressuring your H. But the things you really love and want to hold onto-- keep those.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing