Justifying taking time is easy, doing it is a little harder for a lot of people. But justifying it, if you don't take time for yourself you will implode (fail)

Justifying taking time is easy, doing it is a little harder for a lot of people. But justifying it, if you don't take time for yourself you will implode (fail) and when you do you will lose your client(s) and all your income. It is seriously that simple. While I know it is that simple to justify, all of us that have been consultants where our money is dependent on our time understand where you are coming from, so you aren't alone in this. Based on your description though it seems like you are scared of your client taking work away, if true, this is a horrible client to have. The best way to solve this issue is to find a new client. I am a little confused though as you also call them a partner company so I am unclear what your relationship is, but either way it sounds unhealthy and you need to change it. Either you need to set new expectations and new boundaries or you need to find a new client and get away from them. I always set boundaries at the beginning of an engagement, and I would always set the expectation that if a contract was 3 months or longer that a developer would take around 2 weeks of vacation. So even if the dev didn't take time during that contract and did it after or before, the expectation was there so everyone was on the same page. Plus good clients don't want you to burn out because then they lose out on your services too. When you have a client that doesn't respect you and you've allowed them to dominate you it will never end well. You have to set clear boundaries and expectations early on, doing it later is possible but it isn't easy. Basically, if you don't fix this soon and take a little time, you will fail by burning out which is much harder to overcome at that point, and can take much longer to recover as well. So best to address this now and not wait.