fps is slow

i tried playing the game last night but it had problems with the launcher updating last night, the next morning i tried again and it updated just fine and i was able to play. now that it updated i made a new  installation, i ran the game without mods or shader packs then quit the game and put in my mods and shaders but when i tryed to play my single player world its fps was very slow. i can try deleted my .mincraft folder and starting over again to see if that fixes the problem