Most founders are confused about what should they be focusing upon. As Kotler said, outsource everything except for marketing. You can at least organize your business such that you can focus on marketing.

It is best to outsource non-core activities like Accounting/Book-keeping, Hosuekeeping (security, cleaning etc.), marketing support i.e. development of collaterals.

As soon as you can, you should also consider delegating Development, Operations and even Sales. You should be involved in setting strategy for each of these. You can take help of cloud based CRM & ERP software to get the reports and analytics. This will help you monitor the activities and the goals you have planned for the strategies to be successful.
This will allow you to focus on Marketing.