Disastrous Dramatic portrait

I loved this photo and was desperate for it to turn out well - it the more I worked it the worse it got
As I added coloured pencil the skin tone stared to go a strange colour and then I tried to blend it away a little and the background went really splotchy
The more I tried to correct it the unhappier I got so I’ve ended up screwing it up and throwing it in the bin. I don’t know if I was using the wrong type of coloured pencil, the wrong colours or had the wrong technique (never having played with coloured pencils)
Help please Kendyll and everyone else - what do I do differently?
Apart from everything