Seriously... This kind of treatment is what leads people to go on a shooting spree, get out of there now they obviously don't value you at all.
If this is happening to you,you can bet it's happening to many many other workers. I don't know if you can afford to sue your employer. The employer will no doubt have more money than you do. The absolute best way to protect youself,is with safety in numbers. That means joining a Union my friend. The Union has money and they can afford to go to court on your behalf. I don't know what your labour laws are,but rest assured the Union does, and the Union will also have Lawyers. Unions have done more to protect workers rights than anything legislated. Trust me,join a Union no matter where you find employment.
Good luck finding a satisfying job, you sound like a decent person who just wants to do an honest days work and you deserve to be happy while employed. Hope your stress is over soon. I agree with the others who say you should sue if it's possible and I hope you win a decent settlement to cover the distress you suffered.
