Hey
I was on a holiday recently. 2 Weeks in Egypt.
Let me tell you that i had the same feeling as you. Thought that i couldn't take a break because there is work that has to be done, or a client that has to be taken care of.
I did go anyways. I'd rather enjoy my life rather than work 15 hours a day for 3 - 5 years and fall into a depression. You should definetely go on a vacation! If your friend cancels on you, then go take another friend with you, or go by yourself.
If you have stuff that you have to do beforehand, then plan it out before you leave and go on vacation. Got a client to take care of? Hire a Freelancer and let the Freelancer take care of it, while you are gone and enjoying yourself!
Also, you can check out my thread on this, before i went to Egypt i was going through almost the same feelings as you right now :
https://www.blackhatworld.com/seo/s...can-you-really-relax-your-experience.1121535/
Have fun on your vacation, where do you want to go?