You can't deduct medical expenses that way.
If you buy a policy, you may be able to deduct the premiums as a business expense, but not other out of pocket medical expenses.
If you buy a qualifying HDHP and have no other disqualifying coverage, you can contribute to an HSA--those contributions would be reported on your personal tax return, not on schedule C as a business deduction.
If you have funds in an HSA, you can use those funds to pay for qualified medical expenses for yourself, your spouse, and your dependents. Qualified medical expenses are out of pocket medical costs but not insurance premiums. You will save more in taxes if you pay the expenses from an HSA instead of trying to take the medical expense deduction as an itemized deduction subject to the 7.5% limit.
