I just failed an assignment that was worth 25% of my unit and now I'm really worried.

hi guys, i just got my grade for an assignment which is worth 25% of the total unit mark and i only got 15/100, this was a group assignment and i had to do it alone because my groupmate was not cooperating and i really did poorly on this assignment.

i only have 4 assignments left (20%, 40% and 15%), do i have a chance to pass the unit? what should i do to improve my grade? should i report back to the lecturer, is there any chance to change the grade of the marked assignment?

what should i do if i fail the subject?

pls help me guys, im new to monash and i am very confused now.