How are you able to cope with working 60 to 80+ hours a week on your startup?

What are some ways to cope with working long hours 7 days a week on your startup? I have been working day and night for the last 3 months and it has taken a hefty toll on my health and well being.

I keep telling myself it will be worth it in the end, but some days it's hard to see the light at the end of the tunnel.

1. Get a partner. Someone who understand your goal and agrees with it then work with them to #2
2. Cut your scope, if you already have a customer, most of the time, if you address their major problem and make their life easier...it's a success enough to drive you to build what else they need
3. Remember a version of the 80/20 rule....20% of the product address 80% of the market.
4. I take weekend DAYS off.

If you're able to cut scope enough and still get some success, it will drive you to make it better.