I sympathise with you, mazza . Dental work can be so painful. My parents never took me to a dentist when I was young and I am certainly am paying the price now. A few years ago, I went to get lateral roots removed after suffering unbearable pain, to discover the bone was infected and had to be scraped, as result of my medical conditions. The pain wears us down and it's OK to feel sorry for ourselves, but I am sure things will improve for you. Like you, I suddenly realised that I was getting old, when I noticed my droopy eye and wrinkled neck, especially as I feel 15 yrs old in my head.
Go and enjoy your holiday, despite what you think, no-one will notice the gap or thinning hair, they are probably too busy worrying about their appearance!