Hi I am sorry for what you are going through. :D
Maybe you will not want to hear my advice, so of course you can take it or leave it.
Since you are so concerned about being a man, why not act like one please? A true man does not mean to be proud and refuse to bend the knee. Actually, a true man bends both knees as well as his heart for God.
I know this because my Dad is a true man.
Since you love God, I do not understand how you could curse your wife and her family please? How is this being a true man please? True men are to be strong, and cursing and hating people is actually not strength at all, but a weakness.
James 3 says,
"9With the tongue we praise our Lord and Father, and with it we curse men, who have been made in God's likeness. 10Out of the same mouth come praise and cursing. My brothers, this should not be. 11Can both fresh water and salt[a] water flow from the same spring? 12My brothers, can a fig tree bear olives, or a grapevine bear figs? Neither can a salt spring produce fresh water.
13Who is wise and understanding among you? Let him show it by his good life, by deeds done in the humility that comes from wisdom. 14But if you harbor bitter envy and selfish ambition in your hearts, do not boast about it or deny the truth. 15Such "wisdom" does not come down from heaven but is earthly, unspiritual, of the devil. 16For where you have envy and selfish ambition, there you find disorder and every evil practice.
17But the wisdom that comes from heaven is first of all pure; then peace-loving, considerate, submissive, full of mercy and good fruit, impartial and sincere. 18Peacemakers who sow in peace raise a harvest of righteousness."
I would like to ask you please to consider that passage? God made your wife and her family. Loving them is important. Maybe your wife is not seeing your love for her?
I used to be married, and to tell you the truth, my husband sounds a lot like you. It was only when I left that he did humble himself, but then I was too proud to return to him. Now that I am single, God is working in both his and my heart and if it's His will, we will return together, but we are both GROWING IN LOVE. I am growing as a woman and have realized my faults and sins in my not respecting and loving him, and he is growing as a man and has realized his faults and sins of not loving and caring for me.
Life is a process and God gives us strength, but please I think your focus should be on Love, God's love. This is stronger than any other kind of love. Please if you could ask God to help you to love your wife and her family? If not for yourself and your son (both yours and your wife's son) than for God's glory and to praise Him who loves you and her and him and them?
Thanks for your patience and God bless you.