Ponyo, first big cyber hugs to you for dealing with your dilemma. Life can be trying can't it?
If we are brought up as JWs we are not given a chance to be objective about anything be it religion, child rearing, sex, politics, history or the future. Their teachings are drilled into our brains plus twe are made to feel fearful of transgressing. This is a very unhealthy mental state which most of us on this site have discarded and enjoyed the freedom to be ourselves after leaving the religion.
For the sake of time and the truth I will be blunt: JW values are a complete distortion of reality. The JW org only want unquestioning obedient sheep-like followers doing their bidding. Of course it's only possible to see this after leaving the organisation.
So as a suggestion try and separate these three issues: the truthfulness of the JW organisation, your evaluation of the importance of your marriage and children and lastly your yearning for your lost love. Look at each issue as objectively as you can and try not to see one being contingent on the other to start with.
It is not possible to have everything we want in life, the poor have limited choices and who says that the rich are always the happiest? So it has to be a matter of priority, putting what you need most first, and what you next need most second etc.
Will you be able to live with yourself without Leo? Is the idea of being with Leo just a fantasy and might getting together with him also be followed by disappointment? Would a temporary separation with your husband be a possibility? What if the Bible is right? What if JWs are right? What if they are both wrong? How would the children fare if you divorced their father?
What then is the most important thing in your life?
Naturally you are the only person to decide and you are still young at 28 whatever you think.