I've founded four successful businesses over the past 15 years. Here is what I have learned. The 'emotional ups and downs' are part of the process and are usually driven by doubt and uncertainty about yourself, the market, the competition. These fears are compounded by not taking the proper steps to ensure your success.
A very common mistake is not having an actual plan. At the very least, you should have a completed Lean Business Model Canvas. This is a very helpful tool, it's a business plan on one page. When done properly, it can help guide many of your decisions, and give you a clear path to success. Along with your LBMC, you should have a marketing plan. This can be as simple as attending local networking events and building word of mouth referrals, or as complex as designing an automated lead generation website.
You also need to realize that not everyone wants what you are selling. Most business owners make the mistake of assuming that 'everyone will want what I have,' and this is rarely the case. The key is figuring out who actually will buy what you are selling and focus on that audience as a first step. It's much easier to build momentum and success when focused on a niche.
Entrepreneurs also assume it will be easy to find clients and customers. It's not, it takes times to develop relationships and build trust. You have to focus on getting those first buyers, and then treating them like gold so they a) buy again and b) tell their friends.
The ups and downs come with the territory, but if you have a solid plan and realistic expectations it's much easier to focus on moving towards your goals with a solid game plan.