Can you tell me how i could stop hypomania going into full blown mania?

Mania is a...: very intense anxiety state and hypomania is just below that, but heading in the manic direction. Start by getting as much sleep as possible, cut stimulants and other drugs, exercise your brains out (if you are fit) and look at your diet (allergies, bad reactions to other junk). Then, go to a licensed professional and learn ways to relax--meditation, self-hypnosis, autogenic training, etc.