How to hide scars and embarrassing marks?

I was born with a lot of "deffects" I would say. I was born with scoliosis, bunions, and a lot of birthmarks. Well I had surgery for my scoliosis when I was 12 but now I'm 16 but I have a very dark pink lumpy scar on my side, it's about 7 inches now and I wanna cover it up a little, my doctor suggested injecting steroids into it but since the scar is near my ribs, it would be very painful. Anything I can do to make it a little lighter for this summer? Also Ive had to get my birthmark removed (it's an epidermal nevous) and there's a little scar there, I'm not really concerned about that but I am concerned about the acne I have around it. I have acne scars all on my back and I really need help on covering that up, it embarrasses me and I use washes my doctor proscribed but it doesn't get rid of it completely. Any make up solutions or anything that can help me cover my skin problems. PLEASE HELP!