Time management as a TA in mathematics I just started being a TA in mathematics at a university in continental Europe. My big problem is my time management: I feel like I don't have time for my own research. During a working time of 40h per week, I usually have the following duties (other than my research):


Teaching duties 3h
Attending two lectures (total of 3h) plus their exercise sessions (total of 2h)
Attending a seminar of 2h
Solve exercise sheets of the two lectures I attend
Think about good exercises for the course I'm a TA of
Write solutions to the current exercise sheet


If I include the last three points with a total of - say - 7h (which is probably too little time), my duties in the week take around 17h. Well, this does not sound too much. I do not have to attend these lectures and the exercise sessions, but my advisor strongly recommends attending, as their topics are very important in my field, although they are not at all related to my current work.

But, of course, there are some other things which prevent me from working on my stuff:


The two lectures I'm attending are right one after another. Between these two lectures, I have a break of 30 minutes. But in this short period of time, I cannot be productive. When I finally got started working on my research, I already have to attend the next lecture. This problem occurs a lot for me: during my teaching duties and another duty, I have only one hour to do something. But in this one hour, I mostly have to prepare for the next lecture/seminar/... - Basically, my whole Mondays and Tuesdays are blocked by problems like that (I cannot be productive in just one hour - it's just too little time to get started). 
Prepare seminar talks for the seminar mentioned above. This is not a regular work to do, but nevertheless takes a lot of time.
As my two lectures are on the same day and there is only a 30min break between them, I usually feel very tired after the second lecture. This decreases my working efficiency by a lot. I do take some lunch break after the lectures, but I usually feel even more tired after the break.
Attend seminar talks which take place on a irregular basis.
The only day on which I don't have any duty is Friday. But on Friday, I'm usually really tired as a consequence of the stressful week. Therefore, I cannot be as productive as I should be, even on Fridays.
As I just started being a TA, there are many "small" things which have to be done. Set up a new computer, find out how to use SSH on this one, ... - those small things add up and end up costing a lot of precious time.


I also considered working on weekends, but this would be too much for me; there have to be some days spared for regeneration. Sometimes I think about the exercise sheets of the two lectures on weekends, but nothing else.

About the two lectures and the seminar: I really want to attend those to broaden my view of my field and learn new things which are (currently) not important for my work. One could think about not solving the exercise sheets of the two lectures, but then I won't learn a lot by attending these lectures.

So my question is the following:

How do I maximize my productivity as a TA (in mathematics)?

(Closely related: How can I stay being concentrated after two lectures/on Fridays/...? How do I maximize my productivity-to-time ratio?)
I would like to point out that life as a graduate student is tough, especially if you indeed want to achieve something. 40h/week working time is much less than one should normally invest in. (At least from my personal experience and my personal observation)
Things are just bumpy in the beginning. It's normal. Just keep moving.
You are not superman. Everyone has limited energy and time, you just can't do everything in the same time. You may want to give up one of the lectures that you are attending if it's not closely related to your topic.
Plan your own research, set milestones and keep progressing. 
Try to do one thing in a day. If you work on your own research during the weekends, do not think about your TA duties or lectures at all in the same time. Make a bigger chunk of time to work on one thing instead of fragmented pieces of time is a good idea for improving productivity