I'm in my last term of my MBA program- I've been a full-time student for just over two years while also working full-time, so I can relate. This semester is the first time I've had to enroll in three classes at once (in order to graduate in two weeks- I can't wait!), one of which is the capstone, so more intense than other courses. A few weeks ago, I was stressing over a work project, all my assignments, plus a major life change (I'm moving to a foreign country next month). Something had to give. So I asked my boss if I could take a Monday off, and I spent my three-day weekend catching up on homework and was even able to get ahead with some assignments. Because I got ahead with my homework three weeks ago, these last few weeks have been significantly easier, even though my work project and moving plans have been more intense.
You need balance in life. It's great that you want to study a new topic and I'm an avid supporter of lifelong learning, but you need to evaluate how important this class is to you and if it's worth letting it affect your health and personal relationships. If it's a short-term class you just need to get through, maybe you can buckle down and see it through. If this is a long-term thing, you need to figure out what your sustainable output is and then scale it back to that level so you don't burn yourself out.