@spookytapes: I used to have the same exact problem with the 3DS; so, I got a Nyko Power Grip. It made it thicker, allowing for a better grip. Plus, it basically tripled the battery life. I've been so happy with it, and I would highly recommend it.
You can pick them up online or at GameStop for pretty cheap.
Would you also happen to know why you cannot heal yourself if you are a healer? I find it odd that I can heal all my teammates that are adjacent to my healer but she cannot heal herself? However, I do know it's Japanese game and they always have strange rules :P
Yeah, you can't heal yourself as a healer. You can use items on yourself though.
Just like attacking, healing is only on other people.