Partner has a suspicious mole

My partner has a mole on the side of his thigh towards the back. It's 3 different colors different browns and black and light tan even a possible dark yellow. It's crusted and he pointed it out to me in conversation. 

I then took a photo and see some worrying stuff online so sent the photo to the doctor and they called him this morning saying they need to see him ASAP. Both of us are terrified and we are going for his appointment at 4pm. I can't help but be so panicky and it's horrible seeing him panicky. 

I suffer from tumors so I know how his head is feeling and that's helped somewhat for both of us but this is looking pretty serious and me and my partner are all we both have. He's my best friend and my favourite human on earth. I can't stand the thought of losing him or him going through some horrific things.

I was wondering if anyone's been through similar?