After waking up (3-4, 30h) i can't seem to fall in to deep sleep. its like im dreaming but not actually sleeping hence i wake up exhausted. why ?

Non restful rest: You may have what is called middle insomnia. However, the only way to really know what is going on with the brain when it is asleep or in a phase between sleep & awake is by use of a polysomnogram (or sleep study). Have you considered a small glass of warm milk upon awakening. The heat creates tryptophan which will help to fall back to sleep.