Don't fret. I've found that playing conservatively and keeping the soldiers that aren't moving forward in overwatch mode helps a ton. Try to lure the enemy into your killzone of overwatching dudes and see if that helps at all. Also, I've been focusing on defense upgrades for my soldiers as well.
Honestly, this is all I could have ever asked for and more. Big Boss and his time period has been my favorite since we first saw him in MGS3. The Cold War setting is interesting, and not often used. Big Boss to me is more intriguing as a character then plain old Snake to me, and I love the quazi-futuristic-retro tech.
I have a strong feeling, although with nothing to back it up, that Ground Zeroes will feature the final chapter of the rise of Big Boss, and will lead into MGS5 being an actual remake of MG 1 and MG 2.
Best news I could hear. It's time to get back to sneaking like a BIG BAWSSS! Also, guys, it's not Solid Snake. It's Big Boss. He's got Cold War era equipment, an eye patch, and an MSF Logo. LIKE A BAWSS!