Being an entrepreneur is one of the toughest of challenges.
One of the main reasons it is hard is because whether or not you succeed is not directly related to the amount of work you put in. You can work every available minute and still not succeed.
So for your mental health, to be able to do it in the long term, you need some definite wins happening in your life. Without any definite wins, if your business is not succeeding then you risk surveying your life and seeing nothing but failure. That's bad.
Fortunately there are things you can do in life where there is a direct relationship between effort and win. This means that if you put time in then you get a guaranteed win.
Take some time to do these things so that you definitely have a life that is at least partially winning. Make sure you are getting in some of those guaranteed wins. The price will be that you need to take time away from the business in order to get guaranteed wins. See this not as time away from your business but simply part of the time you are putting into your business. Your business success requires investment of your time not only directly, but indirectly by investing in yourself - this is essential.
The easiest guaranteed win I can think of (and Jeff Atwood pointed this out to me in a post sometime) is to become fit. If you put time in one hour a day, five days a week, you are guaranteed to win. Fitness has a direct relationship between time and effort and result. Unlike your business, if you put in time and effort then you are guaranteed the outcome.
When business is hard, when things are dark, when there are huge problems, you will be propped up strongly by the win you have put in the bag by committing time to your guaranteed wins.
One final thing - take the daily decision making process out of the equation - just stop that daily question "Do I want to commit today's hour to my guaranteed win? The business is so busy, it needs me." Make an up front decision that daily wins get priority over the business time and never again ask yourself "Should I do this today or not?" The question will come up every single day. The answer is "I already decided what the answer is.".
What other guaranteed wins are there in life where time committed = success? Keep an eye out for them.
A life partner, one not afraid to get their hands dirty doing what needs to be done for a vision outside the mainstream paths, grow with them through the fails and the folly, and experience two lives in one lifetime. Find someone to remind us of why to be humble through the successes that can blind one to appreciation and the efforts of others. Someone who does not see us for success gotten, but for the inevitable happiness and richer gain from a partnership with an equal of good character.
Children, to see the world through innocent and new eyes. To see value in things we take for granted, and to give us a reason to think of the future as a prospect even though much of our prospecting years may now be behind us.
It has never been a better time to be poor. What we risk with all the other wins beside family is a life without riches. With others we can know ourselves better, be more whole, understand what makes us human and what drives us to betterment of ourselves and humanity.
The ups and downs of life is the most enriching experience, to know genuine empathy and share sincere hopefulness. One can find such experience in family.