I ve been having restless sleep for 8 months often feel dizzy and feel pressure in my chest. what it could it be?

Anxiety likely: At your age, heart disease is unlikely; more likely isr panic disorder or generalized anxiety disorder, the latter is "the worry disease." look at what you are thinking about during these times; are you going over and over events, trying to anticipate the outcomes of various decisions that you must make? Do yo find yourself lost in a maze of contradicting solutions? If so, its anxiety.