If it's any help I was 35 and a single mother to one (hard work) boy when I met DH. I had been told by a 'player' type that I would find it difficult to meet someone who would 'take us both on'.
But I was told the opposite by far more men- including my own four brothers.
I met DH on a very, very drunken hen night in a nightclub. I wasn't going to go as I'd fallen out with the bride a bit, but decided to anyway.
It turned out that we had both been on the same dating site at the same time but hadn't been 'matched'-possibly because I was/am a smoker and he had specified non-smokers, possibly because I was out of his 'preferred' age range (I'm 5 years older than him). Or possibly because he didn't meet some of my specs.
If you've been quite...strict with your preferences, it might be worth opening them up a bit. Not saying you have to throw away your principles on important issues, but maybe there's some wiggle room?
Do what you enjoy, too. My mother was adamant that I wouldn't meet anyone 'nice' in a nightclub- but I figured, I'm nice, I like clubbing, the odds are that my male equivalent might be out there.
Try, too, something in the martial arts line, if you think it might suit you. Lots of nice-looking (and nice) men in my club!!!
Incidentally DH was single, no children when we met. Tall, dark and handsome, too. And, erm, quite well off.
One last story.... a friend of one chap I dated met a woman with two children and married her a couple of years later. He was delighted that the woman he fell in love with had children- because he had been told he could never have children of his own and had given up hope of a family. Those children were an added wonderful bonus for him.