so this is something i have been working through this year these are the following things that have helped me  1 when approaching a first draft or a plan i say to myself- i am going to write the most rubbish script ever what this does is allow me to override my overthinking with writing its really the rewrite that is where the genius comes but when you cant get your thoughts out to create a first draft that can be rewritten this becomes a challenge this technique helps me push through that 2 literally half the battle is getting my bum on the seat - that is the challenge i must overcome more than anything - so my advice would be just sit on the damn seat or whatever your equivalent is i then set a timer for only an hour or could be 20 mins and i say im going to write until the time is up it doesnt matter if its good or not inevitably i will continue to write if i dont cool at least i did 20 mins right 3 look into medication if you feel thats appropriate 4 this one has helped me profoundly - i realise that the act of finishing my first screenplay to where i dont actually hate it and believe its of value equipped me with tools to do the next one the more you do stuff the easier it becomes its like your brain goes - hey that was hard but you did it so you can do it again this part grows and you build confidence and that helps drown out the noise  hope this helps