What should I do regarding my desire to marry another woman because my wife does not sufficiently satisfy my needs, given that I know of her intense love and kindness, her complete rejection of the idea of another wife, and my unwillingness to divorce her?

The real problem the questioner faces is looking at women, even with the intention of marriage. Unlawful looking weakens faith and increases aversion to the first wife. It is forbidden, not sanctioned by any law, nor accepted by human nature. A man is permitted to marry up to four women if he is financially and physically capable and just. The permission of the first wife is not a condition. A man must assess his need for a second wife, his ability to bear the responsibility, and perform istikharah (prayer for guidance) before proceeding.