I know what you mean i got my first child 3 moths and 1 week ago and i started collecting ponys and dolls again and i have the same though.
But my son donĀ“t need much and i think it is okay to collect if you really love your collection, in my case i will still collect but more responsible and see that i have money for my son if he needs cloths or other things
I love my son and he will come first and if i have to stop collecting i will do it