Is the contract binding the wife to her first husband considered legitimate, given her knowledge of the husband's failure to adhere to the terms of the agreement, which include keeping her away from him and providing only meager financial support for the children? And does her hatred for her husband and mother exceed the bounds of Sharia?

You should make things easier for yourself and focus on one concern: the pleasure of Allah Almighty. Recite frequently the supplication: "O Allah, I hope for Your mercy, so do not abandon me to myself for the blink of an eye. Rectify all my affairs for me. There is no god but You."

If the return to the first husband was with a valid, Sharia-compliant contract, then the marriage is valid. The conditions stipulated by the husband, such as abstaining from intercourse and not providing maintenance, are null and void, but the contract itself is valid. He is obligated to have intercourse with you and provide maintenance for you and your children. You have the right to take the matter to a judge or take from his wealth in a reasonable manner if that is not possible otherwise.

Attempting suicide is a major crime that necessitates repentance. The right of the mother is immense, so it is not permissible to abuse her in any way. Likewise, contemplating killing the husband or mother is among the greatest sins. You must fear Allah and be patient.