Yes, this freeze you are talking about is basically the minecraft launcher loading up the texture pack, dont worry I use sphax and it "freezes" my game aswell. Patience. It WILL load eventually.
IGN: SWVgaming Age:13 Skype (is a must): SWVgaming Time Zone:GMT 0:00 Time of day you are available: Around 12:00 - 01:00 but i can do all nighters. How long you are available for: Erm. ^ Position you are applying for: Miner