There aren't logical fallacies, only misunderstandings of God and biblical teaching on your part, so it seems.

> Then why am I nearsighted? Are you suggesting it’s my own fault?

I am not suggesting your nearsightedness is your own fault. But neither is it God's. Nearsightedness is a condition derived from biological processes: genetics and mutation. Some of us develop nearsightedness, some farsightedness, and many other conditions. It's the cause and effect of biology and human life.

> And if it’s not god’s will that I’m nearsighted, and yet here I am, nearsighted as f***, then doesn’t that mean god is not omnipotent?

No, it does not mean that God is not omnipotent. God's omnipotence neither requires nor even demands that there is no frailty to being human and no weaknesses to our human bodies. It means God is able to do all things that are proper objects of his power. He can never be overwhelmed, exhausted, or contained. He has complete power over nature, though often He lets nature take its course, because that’s what He created it to do. Your nearsightedness is neither God's fault nor your own, nor is it a defeater for God's omnipotence.

You say nearsightedness is not part of god’s plan. Then why am I nearsighted? Are you suggesting it’s my own fault? And if it’s not god’s will that I’m nearsighted, and yet here I am, nearsighted as f***, then doesn’t that mean god is not omnipotent?

You are making a deep mistake to think that everything that happens on Earth is God's will. The Bible is quite clear that is not the case. There are many things that happen that are not what God has willed or God has caused (such as human sin: lying, stealing, murder, adultery, etc etc). Near-sightedness is not part of God's plan. Appendicitis isn't God's will. Infertility is generally not part of God's will. Instead, God's will in the Bible includes us seeking medical care, the wisdom and ability of people who can heal, work to preserve life, and attention to human needs. It seems you are starting with a false premise and are then led to a false conclusion of arbitrariness on God's part. Rather, the Bible is clear that our human bodies are frail and are beset with weakness and vulnerabilities. It is the inevitability of human life, since we are not divine. Let's talk some more.

Where do you draw the line between “god’s plan” and human will?

If nearsightedness is part of god’s plan then shouldn’t christians abstain from wearing glasses? If appendicitis is god’s will then shouldn’t christians abstain from getting surgery and just die? If infertility is part of god’s will then shouldn’t christians refuse IVF? If a woman and baby dying in childbirth is part of god’s will then shouldn’t she refuse a lifesaving c-section? Where do christians draw the line? It seems extremely arbitrary to me.