Okay I realized that most of my stuff in this book is just criticism so I figured I could drop some actual tips!!!
1. development- when trying to make a character develop either in a good way or bad way you have to subtly enter their changes. I mean coming out and saying "this is my development" isn't gonna be good you have to think. So if your OC is developing from a shy girl to a strong woman have her raise her voice and then be shocked after. Have her oppose authority and then feel really really good about it. Trust her gut instead of do what's told and if you do it right then by the end of the story your character is doing this stuff all the time, and emotional development is actually the best thing ever
2. describe your scenes- when you just lay out a setting,an action,and a character I mean it gets the point across. But people like to feel and imagine what they're reading. Give the readers something that they can easily imagine. Describe the setting a little more, what color is the sky, what does your OC hear in moments of silence, give the scene meaning for fucks sake. Describe your character action and give them a reaction. EVERY action has a reaction. Don't be boring!!! Show your readers some feeling behind your words!! Adjectives are key my friends
3. Romantic feelings- I know that people fall fast and everything but you can't have your OC notice,fall in love with, and marry the love interest in the first 5 chapters. Unless there's a time lapse or something but seriously. Love takes some time...even if it's love at first sight or something your character still does not know their love interest. Let them get to know each other. Build an actual relationship not just a romantic one.
4. Writers block- I am the absolute worst person to be saying this but you can overcome writers block. If I am having it I often read other peoples stories. No I do not mean take other peoples ideas I mean read stories that are canon to my universe and immerse myself back into the world that I'm writing about. Sometimes a different story or point of view can go a long way.
I hope this helped a little