Welcome. Do you have an accountant??
I am a Quickbooks Consultant and would be happy to advice you in
keeping your books, (FREE at NO cost)
You should have a separate account for your business. However, depending on your business structure(1), its not the end of the world that you don't. Lots of people do what you're doing. Just make sure that you only deduct the proper items on your tax return and have documentation for it. As a business, you're suppose to keep accurate records which really means you need to be able to prove your deductions are deductible. While you can certainly pay your personal bills with company money, don't deduct those on your tax return. If you'll be providing financial information to a bank other third party, you will need to properly account for your income and expenses (GAAP) so that your financial statements are not misleading. If you can't do that, maybe you should seek the help of an accountant. Additionally, its to your benefit to properly account for your business financial's. Its important to know if your headed uphill or downhill before its too late.
1) you don't want to risk your limited liability of your corporate or LLC status by 'Piercing the corporate veil'.
Brandon Sheffield, CPA
'Accounting that opens the door into your business'