I've written about how to get through second acts problems a few times now, and there's one thing that screenwriters always seem to have in common when they share advice on the topic:
I've yet to meet a writer that just loves writing the second act of their screenplay, and that includes Disney writer Ricky Roxburgh ("Big Hero 6: The Series," "Saving Santa," "Rapunzel's Tangled Adventure), whom I quote above. I asked him if he has any tips to get through second act challenges, and he began, "Oh god." So if you get the same feeling, you're not alone.
I've heard of this trick before, but Ricky takes it a step further.
I'm sure you've seen second acts that seemed like they just dragged on. To avoid this, make sure plenty is going on. The second act is all about obstacles. Each sequence should center on an obstacle that gets in the way of your protagonist reaching their goal, and those obstacles should get more and more extreme.
Your protagonist is set on their path and now needs to try to solve their problem. They'll probably try something easy at first, and of course, it fails.
Consequences of First Attempts
Whatever your protagonist tried before has only made matters worse.
B & C Plots
Bring in your subplots in your second act, which should intertwine with the central tension and reveal more of the protagonist's emotion.
The first culmination is in the middle of your movie. The protagonist has either tried something and experiences some success or their lowest low, depending on the genre.
Midpoint Mirror and Contrast
Keep in mind that your film's midpoint – whether that's a win or a loss – should be mirrored in the conclusion of your movie. Before the end of act two, you'll want to contrast whatever your midpoint was. If it was a victory, the contrast would be a failure and vice versa.
Now that the character knows what NOT to do, they'll attempt to solve the problem correctly.
Character Arc, Part 2
You established your character's flaw in act one, so in act two, make sure you include your character's attempt to overcome that flaw. Where is your character headed in their personal journey? This is the middle of that arc.
The main culmination is the turning point where it looks like all is lost.
Your protagonist resolves that main culmination, but there's still one more step to get to their goal in act three, and act three begins …
I feel better already,