Starting or growing a business is never easy. You need to wear many hats. Sometimes when I ask someone what they think ownership will mean they respond with words that are specific to what they are selling - their product/service or keeping clients happy. While those things are absolutely necessary - you can't have a business without something to sell and someone to sell to - there are so many other things that are also necessary. That old expression "The buck stops here" suddenly becomes really apparent.
You are the person responsible for EVERYTHING (gulp)! You must plan, brand, market, negotiate, sell, handle or oversee bookkeeping and taxes, know the regulations and comply with them, and so on. Years ago when I opened my first business, it often felt like it was me and my four walls. When I hired staff, I felt that way even more because I then also had a responsibility to my staff and, of course, if anything went wrong I couldn't tell them (aka: I couldn't worry them). At that time I was unaware of all the support services that exist for small business, both for a fee or free (government sponsored).
When I work with businesses today, and the owners start to get overwhelmed, or the hours don't seem long enough to actually take care of "everything", I suggest that my clients reach out for help. That could be joining forces with another like-minded business owner to share marketing initiatives or hiring a virtual assistant; it could be joining a trade organization that hosts relevant workshops on how to improve business skills or taking a night course; or it could be setting a meeting with a free business counselor at a business development center. The supports are there - never hesitate to ask for help.