Rather than focusing on trying to do counters, you should be doing evades (A, A and direction, I think). You're actually invulnerable while doing it, and it's a great way to keep yourself from being boxed in. Plus you don't need to wait, you can do it immediately after a move and you can evade every single enemy (even the bigger ones)
Also try and get the critical strike timing down. Once you hit a 4x combo, it kicks in and after 12x you enter bullet time mode where everything gets easier. I stopped doing counters because it's too easy to lose your combo or get screwed over by someone off screen.