You do not get a second chance. If you kill yourself you are dead, that's the end.

This is not about weed, nor about solipsism. You show extremely obvious evidence of having an anxiety disorder with obsessive thinking. You had this when you were a child, though there were years when it did not trouble you.

You are now applying your talent for obsession and anxiety to the subject of seeking help. Psych meds do not turn you into a potato, they set you free from your illness and let you be your true self.

A diagnosis is the first and unavoidable step to getting help. If you can get by without help you would not be diagnosed with an illness, so there is nothing to lose.

If you are diagnosed with an illness (trust me, you will be) then you need that diagnosis to get the treatment you need. There is no way around it, you can not get effective treatment without a diagnosis.

Without treatment you will further mess up your education, your career and your acquisition of social skills. Your mental health will get worse, the treatment you need will become more expensive, and you will outgrow your child's entitlement to have your parents or the state pay for it all.