I know there's probably no 'real' advice anyone can give me but I just need a chance to talk/vent whatever.
I'm 32, almost 33. Most of my friends are married or in stable relationships (I know this could change!) Many have children; those who don't probably will in the next three/four years.
I've had a strange sort of life. I had an 'ordinary' childhood - quite middle class - but that started to change when I was 13 and my mum was diagnosed with cancer. My brother has autism and always got more attention than me anyway and when my mum was ill I became pretty much invisible. She died when I was 15 and my dad moved out into another womans house and came back every other weekend! This sounds bonkers considering I was in year 10 at the time but everyone just acted like it was normal.
At the time I was washing dishes in a local pub for pocket money and met an older man who looking back was troubled himself. I got pregnant. I went into serious denial and by the time it emerged (as I was barely attending school at this point) and became obvious I was 28 weeks. I had a baby girl and it was generally considered by everyone adoption was best for me and my daughter. That was what happened. My dad never talked about that.
I did surprisingly well in my exams considering and went on to do a levels at a sixth form college where no one knew my 'history' so to speak. I went on to university and my dad died then; and after I graduated I was desperate to replace my family. I had a sort-of relationship with a man - it was never serious and we had a sort of tactical agreement that he'd help me get pregnant 
I got pregnant fairly quickly and soon realised it wasn't what I wanted. I felt alone and frightened and sick and scared. I ended up having a termination (I don't regret this.) This was all quite a chaotic and dysfunctional time for me and I was working as an escort in the city so I was having sex a lot but never actual relationships.
I suppose the point is, I've settled of sorts. I still live a life others probably consider a bit mad (live on a boat, work 3 jobs!) but no escorting or pregnancies or other madness.
But when I see my friends in stable marriages and starting families I feel sad. I have explained my history because I can't contemplate having a baby alone but I doubt very much I can have a relationship (I have had counselling but while it helped me come to terms with some stuff it didn't make any difference to relationships.) I don't want one, can't imagine having one.
But I know as I go from my 30s into my 40s and then 50s my life is going to be so dramatically different to everyone else's and not entirely through choice.
I suppose I am wondering how everyone else deals with being 'different' and living a life that while you're happy you recognise you wouldn't exactly have chosen it!