Like seeing things in my peripheral vision thinking they are something that they are not. (For instance seeing a black bag on the ground in my  Peripheral  vision thinking it is my cat) Even if i go there 2 or 3 times everytime i think it's my cat in the side vision, only to instantly know when i look there that it isn't my cat. Why do i repeat these thoughts if i know it's not my cat?  

I also have a really really bad shortterm memory, i go into the kitchen to make a tea and when i'm there i forgot why i went to the kitchen in the first place. Then i remember and start making the tea and when i'm in the middle of it i forget where i got out the tea from the cabinet while putting water in the Boiler etc. Just silly things like that.

Also speaking a sentence and thinking i used the wrong words or wrong grammar while speaking. It's like when i speak i immediatly forget what i spoke, but I don't tho. Just like i am afraid that i somehow formed a wrong sentence? I know nothing of this makes any sense. Sometimes i think i'm going literally insane. For instance it's late at night and my air purifier is running and it has some weird peeping noises and i connected it to be bird singing ( We have a really beautiful wild bird outisde that always repeats his song the same) and this song immediatly came into my head and repeated even tho i knew there were no birds around and i turned off the purifier. . It drove me mad and into a panic attack.  

All of these symptoms worsen when i am tired, and i never had them that extreme. I think i might suffer from Sleep apnea, i know i sound like an hypochondriac, because i am lol. But sometimes i can literally hear myself gasping for air when being in a kind of half sleep. I was scared to mention this to my GP because i thought maybe he would say it for himself that i maybe suffer from it but he didn't because i am normal weight and don't have any other health conditions but some allergies and post nasal drip. 

Is this all related to my anxiety disorder or am i developing something more serious like Schizophrenia or even early onset dementia? I'm only 27.