Meltdowns with change

It seems lately Cole has either been testing people to see what he can get away with or we have had major meltdowns. This last week I was kicked out of the EI session because Cole was using me to not have to do his work. I was more then happy to walk away since I know that after the session they will inform me of everything they did. It was hard listening to him cry but I knew he was crying to get his way. Recently I went back to work and the started a second job which is suppose to be per diem. The per diem job has me training so I am putting in 2 or 3 days with them and then working my full time job. I don;t know if things changed to fast for Cole and he is having a hard time adjusting to it or if he is just being a 2 year old. What I do know is last night he had one of his worst  meltdowns. It happened when he woke up and it lasted about 40 mins. I tried everything from making him a milk cup, changing his diaper, giving him a snack and trying to turn on a show he likes. It felt like it was never going to end and when it did i think Cole and myself were drained. I plan to really look into different things that might help with meltdowns along with reducing my schedule at my per diem job until Cole is well adjusted. So my question to everyone is have you dealt with meltdowns? Do you have any suggestions on how to handle the meltdowns or make it pass faster?