Thank you everyone for your replies. After carefully reading all opinions I think that TDD is the way to go because for larger projects sooner or later it will help me catch bugs when the project becomes complex. I also think that the 2x effort will be worth it with easier deployments.

I was kind of giving up on TDD but seeing that almost everyone thinks it is important (for larger projects), I will try to watch some more videos and try to write tests for my current project (for the work already done) and tests first for the code that hasn't started (maybe I'll add comments in the tests). This way I can compare the two, with which approach suits me better and fails more (i.e. catches more bugs) in future.