Version 1/8.0 .1

Hi ive downloaded minecraft reinstalled but it dosent seem to work on version 1.8.1 or 1.8 although it worked a few days ago , Ive found that if i switch my version to 1.7.5 there are no problems please help me fix this issue. it freezees the gameplay but not the music and then works again in 1 second and frezes again the next second.