Well done for getting thus far.
firstly your connective tissue wont be back to its pre pregnancy tautness till at least 6 months postpartum so the linea alba will still be a bit soggy. Secondly yes you should wear some pretty strong support so that when you are doing your Transverse Ab exercises, the muscles are in the correct place, not out and stretched. needless to say you dont rely on the support but keep trying to suck it all in. Tubular elastic bandage (tubigrip size k or l) is good worn double or any elastic type wide bandage or "stepin". Keep doing the ab exercises as well.
If after a year there is still some superficial bulging which you dont like, and you dont intend to have any more kids, a small nip and tuck works well, but most people find that it goes back OK Good luck