I was going to do an overpainting but there's too much wrong with this. I'd basically have to start from scratch. I recommend you do that too. Make a proper construction drawing of his facial proportions and work on your values first and come back to this thread with that. You should also post your reference for stuff like this.
Honestly he just looks like the Toxic Avenger at this stage. I wish I was just trying to be mean here but look at his eye positions.