If business and personal money share an account, every month is a sorting job. Here is the fix and the handful of rules that go with it.
Open a business checking account and get one card on it. Every business purchase goes on that card; every customer payment goes into that account. That is the whole system.
When you put personal money in, it is an owner contribution. When you take money out for yourself, it is an owner draw. Both are normal; they just need to be labeled, not called income or expense.
Don't go back and split old statements line by line unless a preparer says you must. Start clean on the first of next month and let the bookkeeper handle the old mixed months as catch-up.
How owner draws and contributions are treated on a return depends on how the business is set up. That part is for your tax preparer.
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