I think there's a serious point here.
We all strive to give our children what we didn't have and become more evolved, better parents than we had, so of course it could be pretty emotionally triggering when we think of ourselves at our children's ages and think of what we might have been going through/ how our children really don't see/ know what we are protecting them from, or enriching them with at any given time, because it's just the way we've always been.
My mum left when I was one (mental health problems) and having a one year old now makes me realise how lucky my little one is to have us so interested in her, so aware of her needs and healthy enough to really give her everything from warm, clean, stimulating environments to eye contact, education, nutritious food and a mum and dad who love and care for each other.
I don't feel jealous but I do sometimes have to watch myself when I'm leaving her with the childminder for example and she cries for me. As I leave her there, I sometimes think 'well my mum had completely abandoned me at this point so you're lucky' instead of being sensitive to what she's going through at that moment (which must feel like a huge blow for her after a year and a half by my side) Of course I am sensitive to this and feel very sad to see her upset, I also have the underlying thoughts that she 'doesn't know she's born' which is harsh.
I think you're really lucky having older children at your age, the baby stage is over and you could now enrich your life in a way that will really inspire your children to follow their dreams too.
I remember when I was 14 and my dad had a massive heart attack and had to be revived with those electric pad things. He was only 40 at the time and his partner (when he was recovering from a triple heart bypass in hospital for 3 months) was cheating on him with a much younger man.
He was such a shell of a person after that episode but slowly built his life back up and went to yoga, made new friends who took him to the comedy store in London, cycled everywhere, taught himself about nutrition and moved to Cornwall where he loved the sea and became a farm hand on an organic dairy farm by the sea, leaving the rat race and his stressful trade behind. My sister and I were so blessed to witness this 'Phoenix from the ashes' reinvention of himself that we have both really gone on to live our lives to the max and tenaciously follow our dreams.
You can still be a very inspiring person to yourself and others - don't feel it's all over, it might have only just begun.