Minecraft not launching

So this morning the game was perfectly fine, then I tried to install a mod. For some reason after that every time I click minecraft it shows my mouse with a little blue circle then goes back to normal.
By the way I tried many websites and java its just not working and everytime I end up trying to test java, it takes me to an update screen. And then when I update it, it stops in the middle of updating and crashes. Sorry this is confusing can anyone help.