You need to get better at the 1 on 1, IP and OOP play of the blinds.

Blind bb/100:

BB:
Acceptable: -40
Good: -35
Great: -30

SB:
Acceptable: -20
Good: -10
Great: 0

If your Blind play was acceptable you would have 'won' or not lost ~$275. If you were good it would have not lost ~$400.

The in and around the blinds are where 90%+ of the marginal spots will be, you cannot play fit or fold, you cannot let a BB run you over when you are the SB, and you have to play poker in these spots.

As far as your cbetting is concerned I think you are fine at 75%. This is only because you are soooo tight that your range would dictate that you have the top of your range on most flops.