I think having what you describe as a "laddish" ppersonality may contribute - I have similar, I'm quite independent/self-contained/have solitary focussed hobbies and work and don't tend to go round in a big group of women.
I'm quite mainstream, but I don't really naturally slot into an all female group
this tends to be a green light for some men.
I dont like seeing myself as vulnerable, but a woman on her own is always seen as an easy target, if that makes sense? It doesn't matter how I want to see myself, that's how people react .
So I don't think twice about attending mixed events solo. Of course, this is 100% my right (as is other peoples right to prefer big groups) and isn't even worthy of thinking about.
However, being not visually "part of a pack" means it doesn't matter how strong willed I am or feminist, people including men see this as "easier" or "accessible".
If I always was joined at the hip with my mum and aunt and chatty Naomi from accounts then it would be harder for men to break past that (but not really my style).
I don't like a herd mentality, but a herd protects as predators target the solo ones.
If you're in your 30's, good job, no kids, I'm afraid you will also now be seen as a potential cash cow and new step mum for a lot of men with young kids looking to jump ship!
The other thing is desperate people and people with less to offer try harder.
Of course an affair with a married guy probably contributes very little positively to a woman's life (unless he's a tycoon offering to buy you a flat or something haha). So they need to do the hard sell and are more pushy.
The guys who are more prizeable on the dating market will be less visible and pushy as they know women will be willing to do more chasing.
I'm sorry you're going through this as its ultimately horrible and demeaning to single women and means you have to be more protective of your boundaries.
I tend to reduce contact now and be brusque or detached (keep work stuff to work email, no-one needs to know my personal details) as I feel a lot of partnered men like testing boundaries and creating ambiguity.
Being more private and emotionally closed helps. I'm even thinking of making up some imaginary strapping sons to put men off!
Again, I think having a direct personality means I can overshare/give too many details and info is catnip to creeps
(ok looking childfree woman living alone = Creep Stampede).
(We all know who will get the blame if Mr Married Casanova makes a move and there's unpleasant gossip - its never the man!).