if i am in the state of major sexual impurity and have not performed ghusl , can i halal a animal to eat? would that be considered halal or do i have to do ghusl first?

Yes, the slaughter is valid and the meat is halal, and you do not need ghusl first. Imam Ibn Baz said there is no harm in slaughtering while junub, as long as you say Bismillah.