Heya, I am glad to hear your story.
I started off only looking to meet women 8-9 years and after not having much luck looked to meet men too. I can't even remember if my ex had problems with me dating men so I'm no help for advice there. I do know I've seen threads on that here, though I wouldn't know what tags to look for, there are some things worth reading on that subject.
For scheduling, I can only hope you have set work hours? I'd probably google calendar the hell out of my life, figure out the minimum time I need with my husband and my girlfriend, and schedule regular dates. Schedule in time and events with my child, and any other non avoidable events in my life, and I'd schedule a bit of time for myself. Then I'd REALLY look to see if I have time available for another relationship. I'd think about if I wanted to use that spare time to try to fit in dating another person, or think about if I wanted to have it be flexibly available to see more of the people already in my life.
I have been open to dating a third person for awhile, and assumed I had time for at least one, maybe two dates a week. However I've been keeping track and have found that with my current set up and making time for friends and myself, even fitting in a coffee date with a new person can leave me feeling overbooked (though some of that is meeting new people stress).
This has taught me that to seriously date another person, I need to be pretty comfortable with them right off the bat, have some hobbies in common, or have them be friends with my husband or friends, I'm getting the feeling I can't handle another relationship that is totally independent, or I'd go bonkers, unless it was limited to a couple times a month. I'm glad I figured this out so I can express this to people I might want to date who might have totally different needs for time.
So you might really find out you don't have time to date anybody else, or think really carefully about what your minimum needs are for a budding relationship and if you have that time available to commit to it. No idea if any of this was helpful, I am getting the feeling there was a lot of redundancy in it as I'm operating on 5 hours of sleep, but wishing you luck!
Happiness will never come to those who fail to appreciate what they already have.