Do the doors in your classroom open into the class or out to the hall? If it is an inward opening door maybe a door barricade brace of some sort would be an option?
Door-brace: (a.k.a. police brace or buttress lock) leans diagonally from the floor to the door to prevent the door from opening - IF you make sure both ends are firmly engaged against sturdy surfaces (or engage in mortised cavities).
The we know 6 made sense. made me cry but made me feel better about how emotional I am!
I'm sorry you are dealing with so much. I feel for you, I really do... I lost a dear friend to cancer in May and it sucked. It just sucked. 34 years old, mother of three. Sometimes I feel guilty just for being healthy amd I wonder why I get to watch my kids grow up and she doesnt and now being pregnant, those emotions are even worse. And a friend with cancer is just one part of all you have to deal with. When I went through it I could barely function and it was all I had going on!
Venting is a good thing. It helps a lot to just let it out. Never apologize for it!