You don't seem to have anywhere near the # of troops or even just brigades to have good success there. You also probably aren't really doing much with just 7 brigades on the left flank. It's possible to use the secondary attack (which starts things off) and make it all the way to Fort Stevens, so if this is all you have to work with I would consider beefing up that side, slacking on the "main attack" with only a few brigades to take the eastern fort, and then putting much more into Flank Right or Flank Left and trying to roll through the entire side from there. (Probably Flank Right, the left approach kind of sucks imo)
Still not a good situation. You really shouldn't be outnumbered in Phase 1 as attackers, considering what happens if you can even win this part.