I am 28yrs old and have noticed the past couple yrs my memory getting almost non existent, irritability. early onset altzhemiers at my age?

Likely anxiety/depre: Probably you are suffering from anxiety/depression and not realizing it..Having these can surely negatively affect your memory. Your mind is worrying about things all the time, u probably don't sleep well, don't feel well, thus you will not remember things too well. I would consult with a doc for an eval..Alzheimer's is not likely at 28. Good luck to you.

Sleep apnea?: Sleep apnea can also cause memory loss. Look up signs of sleep apnea and get tested if you think you have some of the symptoms.

Fix the basics: People perform at their best when they get adequate restorative sleep, regular exercise, proper nutrition and work in a comfortable setting. It also is important that no underlying medical or emotional condition like anemia or anxiety is present. Think through these basics and fix what you can. See your doc for an evaluation and possibly a sleep study. It is more likely you have something common.