Hello , posting here as I'm terribly anxious and reading some similar posts have really helped me. I am 25. 
 

So a few weeks ago I noticed an irregular mole on the back of my left thigh. At first I thought it was new but I have since gone back through any photos of me that exist and can now see that I've had it for years, however as all the pictures are from far away, I have no idea if it has been this very odd shape. I have spent a lot of time in the sun and used to use tanning beds (I can't believe I was ever so stupid)

I saw my gp who referred me to a dermatologist who has said it needs to be removed and tested. I have been physically sick with worry and no today I have noticed a swollen lymph node (I think) in my right armpit. The lump is around kidney bean sized id say and moveable and is a tiny bit tender I think. 
 

My mole is due to be removed Saturday but I am worried sick. I am now convinced that it is melanoma and it has spread to my lymph nodes, the places my mind has gone to I can't even tell you. 
 

Has anyone had any similar experiences or have any knowledge of melanoma/ lymph nodes etc?

Thank you so much in advance