3Feather,
I'm new at this, but I don't think your hand should be pulling in at release. You should try to keep your bow arm and grip pretty solid and stable through release. Now, there may be another reason for string slap, but it shouldn't be from that. If you are canting the bow I believe you should be keeping a fixed wrist and rotating your whole forearm not twisting only your wrist, which could be causing more string slap when you cant.
Just some thoughts from another newbie, so take em with some grains of salt.