I have been feeling weak, lightheaded,headache,confused, dry mouth, sleepy all the time?

Hi I was released from work 4 months a go and for last 3 month I have been feeling weak, lightheaded,headache,confused, dry mouth, sleepy all the time, I feel like I’m always thinks when I am sleeping, unable to concentrate in my new Job.
I have been to my gp and done blood test everything was good fine part from low platelets 132 but the doctors said that’s not the problem and everything is ok but I am still having theses symptoms and it effecting me every day

Age: 22
Male
Medications: None