My first H (now XH) was a wealthy businessman. We lived in a big house, i didn't need to work, I spent years doing 'fun' things and yes like your friend i had fancy haircuts, expensive make-up and we went on lots of holidays. Yet I was deeply deeply unhappy.
On the surface most people thought we had a great life, many were envious. But behind closed doors we had an empty, cold marriage and we just didn't get on. He was very controlling and I started to hate him. I felt like I was wasting my life, everything felt bleak and pointless. I ended up on antidepressants and anti-anxiety meds although I put on a brave face in front of other people so most had no idea.
I was wildly envious of all my friends, who had jobs and independence and good relationships with their partners. One of my friends rented a tiny damp basement flat with her bf, but they were so happy, and I kept wondering why I couldn't have that sort of happiness too. I was also jealous of my single friends, who I felt still had the chance to meet someone special, had so much flexibility and freedom and excitement in their lives. I knew I'd chosen the wrong partner but was too scared and dependent to admit it for a while. Then after a few years of marriage I decided I had to change...
so I studied for another degree, left my H and took a job far away. I divorced my H (a messy divorce that cost me a fortune in legal fees). I lived in a tiny poky flat in a high-crime area with no spare money, no car etc. I worked full-time, did lots of overtime and weekend working to get my career off the ground. It was tough... but exhilarating. I gradually started to feel alive and confident again. I didn't have much time for socialising (and shopping/beauty spas/fancy haircuts were a thing of the past)... but I was happy and had goals. The job was exhausting and not great, but 2 years later I got a better job in a different city and moved to a much nicer area. I also married my soulmate and we now have a baby on the way. I feel happy, content, and inspired by my DH, who I love more than anything. Just seeing his face each day and spending time with him gives me so much happiness.
I don't miss my old life, in fact I shiver a bit when I look back and remember how it was. It may have appeared 'perfect' to many people, but to me it was a horrible way to live. Money, free time and nice things really don't make you happy or make up for an empty marriage. The fancy lifestyle just disguises it a bit and makes it easier to convince people you're fine.
The point of sharing my story... is that your friend's 'perfect life' may not be what it seems. Even if she's happy with her DH, it's no guarantee she has the life she wanted or that their marriage is good (or will stay good) just because he has a successful career. I'm sure there are things she envies about you and other people.
My advice is to work on changing your own life... change your job, go back to studying, re-locate if necessary, and MAKE time to meet men if you want to settle down/have a family. Be selective about who you settle down with... IME your choice of life-partner is the most important thing of all. Choose someone who makes you feel happy and alive, who you love easily and unconditionally. I knew my current DH was 'the one' when we went on a budget holiday together, lots of things went wrong with the accommodation and flights, but we had so much fun, intimacy and laughter that the practicalities didn't matter!
In a few years you could have all the things your friend has, and more. You never know what's round the corner, but you have to work at making things happen and building the life you want.