Different Model when switching to object mode

I have a problem : when i switch from edit to object mode, my object changes ! That is the second it happened to me, i have to start all over again…

You have hidden geometry in edit mode. Select all and look at the top header, it says 60/143 which means that you have 60 vertices selected out of 143, even though you selected all. Alt+H to unhide.

Oh, my bad, i was clicking on “H” the whole time, i though it was deleted !
Thanks JA12 for this quick response.