Im a mid level developer (4 years of work exp in a mid sized company)
With little design pattern knowledge.

How fucked am I, and what are the best resources to learn them? What are the essential design patterns I should know?

Insufficient data for meaningful answer.

@Jilano what additional data do you need?

You're not fucked, you just need some solid experience.

Design patterns at their worse are buzzwords mostly needed to pass the job interview. Design patterns at their best are tools in your repertoire to help you shape your code before you write any as you can wrap similar problems in appropriate code.

That being said: it really depends on what you want to build and what trade offs you are after.

There's no silver bullet.