I wish you the best of luck with your single parenting (or future marriage if you go that route). It takes enormous dedication to be a decent parent even when you have a spouse to help with it, so I don' envy you the job ahead. But I have read stories of good single parents (who have raised great adults.. I can remember one story in the newspaper) so I know it can be done. Just not easy!!! But good parenting in itself is a true challenge.
Just like love, happiness is one of those elusive, not always easy to define kind of things. It can change over time and basically happiness isn't something you find in someone else, it's something you have to find in yourself. If you depend on someone else for happiness they are bound to eventually let you down. On the other hand, if someone makes you very unhappy (i.e. an abusive situation, etc...) then you have a right to get out of it. But I think one problem is that oftentimes people who want to get out of a marriage will sometimes "rewrite" history. They'll see the marriage as much worse then it is, or focus entirely on things they think are bad and completely ignore what was good. It's easy to find excuses to justify behavior (You have PMS, you didn't like my hobbies, we fought too much, we didn't fight enough, we didn't spend enough time together... etc...). Sometimes things are really fixable. Particularly in long-term marriages where people have just been together so long they've taken each other for granted (extremely normal in long-term marriages) and have forgotten their love and why they got married in the first place (I do think if you've loved once it's probably still in there, you just have to dig inside again to find it).
As far as being the OP in a relationship that would be a difficult place for me. Regardless of the chemistry and attraction (which really isn't unique to one person, there are plenty of fish in the sea as they say), I'd prefer to choose someone who's not getting over a relationship or marriage, and therefore doesn't have a bunch of baggage to deal with. Relationships are hard enough without having to deal with a bunch of leftover crap (forgive my french).
Why not choose someone healthy and together rather than someone lugging a bunch of garbage with them? This is my own personal opinion of course. Some people like to try and fix other people or feel helpful to them. Look close enough and all the little dysfunctions start to emerge.
There is no arriving, ever. It is all a continual becoming.
