Skin problems skin lightening i realy need help please anyones who has this problem help?

okay so my knees are very dark and i have a very light skin tone its like the color of carmel and then my knees look like the color of a milk choclate hershy bar. this is very embarrasing so i purchased meladerm. in about 3 weeks i noticed a skin color difference on my knees they were about 2 or 3 shades lighter. but they were still very dark. also i am supposed to avoid mosquito bites or just getting bruised because if i do when it heals it leaves a dark spot the same color as my knees so i put the meladerm on the spots too and it did nothing for the spots. i was trying to avoid hydroquone products but its getting to close to to the summer and i will not go to my 8th grade graduation with my legs lookin the way they are. to look and see how perfect alll the other girls look incluing my friends would be a nightmare so now i dont care if it has hydroquone i just want the discoloration on my knees gone and the terrible mosquoto bruised dark spots gone and i am so sick of getting discuted looks from people when i wear a swimmsuit because of my legs because the think my knees are just dirty.its not far i have super long legs and i good body shape but during the summer no guy or girl would want to talk to me because of these so noticeable flaws so i need a strong product that works quickly something that will have them gone by june 9th thats the day of the 8th grade graduation and the dance where i have to dress up and stuff and if i cant get them to go away i will stay at home and dream my own 8th grade graduation. but i realy dont want that so someone please help