I truely think at your age or my age, the chance of having a man who is both nice and available is very small. The only possibility is that such man:

1. breaks up with his gf or divorces with his wife.
2. the termination of the relationship is not due to his own problem. Maybe the woman didn't realize that he is a nice man, or the two persons simply didn't fit.
3. he is ready to pick up another relationship with others. Some people choose to cool down for a period...
4. you apear in front of him, in the right place, at the right moment.
5. MOST importantly, he must be attracted by you.

The 5 conditions above must all be satisfied! See how hard it is?

I also have two good female friends (both are my middle school ex-classmates) who are facing the problem you mentioned. Both of them are attractive ladies, quite successful in their career, and have good family background. However, they both feel very hard to find their Mr. Right. One of them is still trying hard, and the other is almost giving up...

天下英雄, 忠直豪杰言无隐, 志垂日月保江山，

古今八风吹不动天地月, 改尽这江山昔旧，

自古人生谁无死, 留取丹心照汗青。