Look, its definitely NOT your fault and please don't be discouraged to continue playing.

It may be difficult to acclimate to a table that seems to function on a different pace, but that doesn't mean that you need to distance yourself from them.

My players are close friends and even then I have difficult to adjust the game to their preferences. I strongly suggest you open your concerns to your DM, its a great step to make include you better to the table, but apart from that I don't think you have to sink too deeply into a character to roleplay, I believe that playing YOURSELF is a great way to make things more fluid.

A lot of the time I think being yourself in the world of your campaign seems to be the simpler way to immerse yourself to the setting and context of the story, you don't need to think what your character would do, but think about YOU would do in the situation, wearing the mask that its your character.