as an english ph.d. student, i love reading fanfiction. the only thing i cannot handle is when people CANNOT PICK ONE TENSE. YOU NEED TO PICK A TENSE. IT CANNOT BE BOTH PAST AND PRESENT AT THE SAME TIME
btw, some actual writing advice: if you are struggling with a scene, open a new document, write the scene, copy and paste on the old one, so you’re focused on that and not with the rest. Breaks the story in smaller units, then you can tie it together in editing.