Welcome diddlina, I'm happy you found us but sorry you are experiencing Health anxiety. Many of us, including myself, suffer from HA. Know you are not alone in this. As Park12 said, try to occupy yourself with something until your appt, I know it isn't easy but do try.
I can't say if it is skin cancer or not, Only a doctor can do that. But know that when found early it can be treated and isn't life threatening. You are doing a great job on being proactive and seeing a specialist, please let us know how your appt goes.
Please check out the below links for health anxiety, I'm sure something there will ring familar to you. Also check out our resources on the top of the page it has alot of self help links.
Health Anxiety - A Self Help Guide:
www.nhs.uk/conditions/hypochondria/pages/introduction.aspx Helping health Anxiety
www.cci.health.wa.gov.au/resources/infopax.cfm?Info_id=53 Health Anxiety- The Super Scanner
www.get.gg/docs/SuperScanner.pdf