That is quite a lot more so this probably won’t help.
Did you enter any self employed health insurance under schedule C? If you couldn't use it all there then the difference goes to schedule A. If your health ins exceeds your net self-employment income it gets split. An amount equal to your net self-employment income goes on Form 1040 Schedule 1 line 16 and the remainder gets added in to medical expenses on Schedule A.
Medical can come from other places, even from a W2 or 1099R.
Did you buy health insurance from the Marketplace exchange? Or have to pay back the subsidy? If you went to an exchange for Health Insurance, and had to pay back some of the subsidy, part of the adjustment will flow to Schedule A.
If you get Social Security benefits the medicare deduction on your SSA-1099 will flow to Schedule A.
Or are you seeing the amount listed for the 7.5% of AGI?