Serious weight loss help.

I'm only 15, male, 6 foot 3 and weigh 400 pounds. that is a lot weight, right? I'm so disgusted with myself and have no motivation whatsoever anymore......Am I at risk for health problems at this weight? I can't even get on the regular electronic scales anymore that you can buy at the grocery store. I either have to go to the doctor or someplace other. I'm gaining weight pretty fast and can't get around that easy. I guess all of this added weight wasn't really my fault because I have some medications that prevent me from really noticing how much I'm eating or in other words I'm always hungry, and I can't really stop these medications, they're really important. any help would make me feel very grateful, thank you.