Can you handle every aspect of self publishing your books? The answer to that question depends on the individual. I believe you can and I have done that for almost all my books. I have used photographers rarely and a graphic artist once or twice but mostly I do it all myself.
It’s a lot of work but it does save money. For me the savings are important but what I value most is the direct control of every aspect. It allows me to make absolutely certain that I attain the level of quality I want and deliver the message clearly in my own voice.
You can get help for many aspects of publishing a book but it’s important to have an in depth knowledge of every aspect so you can evaluate the quality of the work. After all, you are the publisher and fully responsible for the end result, no matter who does the work.