The game starts and I see the Mojang symbol for about 20 seconds then the game crashes

I open the Minecraft launcher and click play. The game opens but is just stuck on the Mojang screen for about 20 seconds then the game just crashes. I have tried uninstalling the game a couple times to no avail and also restarting my computer. The cause of this is most likely because I tried to download the Sphax PureBD craft resource pack that was the 512 version instead of the version better for my computer (128). What happened there was I downloaded it and saw it on the resource pack page in game and tried to select it, I selected it and the game froze. This part is not important but I thought I'd include it anyway, I ran a full virus scan through McAfee and they didn't find any issues. Thanks for the help.