E.W.
T., by freaking out on your son and punishing him you sent him a message that what he did was wrong. However, did you then sit him down after a while and explain to him WHY it was wrong and that he shouldn't do it again? A lot of times we send the wrong messages to our kids by yelling and punishment but not explaining why it was wrong. Also talk to him about why he was trying to get your 2 year old to do that. Who showed that to him? Did he ever do that to anyone before? You will be surprised what a 5 year old can understand if you talk in normal tones and try to get him to open up.
As far as the help you need, do you have a trusted family memeber who can help you or a trusted friend? I would suggest if you have a church that you go to for you to talk to the pastor. Or if you don't belong to a church, join one and ask them for help. You can't go to the police without some sort of proof about the person you think is doing this to your son. That no school will take your son is ludicrius!!! By law your local district school cannot refuse to have him in school because of tantrums. That is the most ridiculous thing I ever heard of! Every school has councilers that will help with the children. Does your school have a special education class? Maybe he needs more help. Maybe you need to spend more time with him. Who knows. Try your local church first, then if that doesn't work, go to the state. Evidentally the father isn't around and you going to school and working your children are suffering. I commend you for going to school but I think right now your children need you more.