@Beaglemum, before you know it you'll be on the other side of chemo. It's a tough journey but like others have said, it's doable. You just have to take one day at a time and be kind to yourself. Do whatever you need for you to survive mentally. Lie in bed and watch Netflix all day if you have to! I had days when I would poke my head out the front door then slink back inside, which is a big change for me as I'm someone who likes to be out and about every day. But hey, I knew it wouldn't last. Oh, and go and speak to a psychologist if need be.
Like you I was (and still am) 'vain'. Although I prefer to think of it as just having pride in my appearance, afterall, we all feel better when we feel good about how we look. I did the Look Good Feel Better program and it was great. I also looked up lots of stuff on Youtube. When I eventually lost all eyebrows and eyelashes I drew eyebrows on every day and used false eyelashes ('Glam' brand from Chemist Warehouse - not too expensive). Check out eyelineherblog on Youtube. She's amazing, she has Alopecia and does lots of videos on how to do eyelashes and brows, even how to give the impression of lower eyelashes when you don't have any and can't use falsies. I'm jumping the gun when you've only just started but keep it in your 'kitbag' of tips if need be. Oh an I also used fake tan on my face and neck every day as it made me look and feel healthier. There's nothing wrong with caring about how you look.
Sorry, don't want to overwhelm you with info!
Take care of yourself, you will get through this and will be able to look back and say 'wow, look how I bloody nailed this chemo/cancer thing! How awesome am I?!'