You need a balance of achievement, exercise and pleasure in each day to keep the endorphins raised. Motivation doesn't come unless you first do something and then it starts to grow. If you sit procrastinating and expecting to feel motivated, you won't.
It's also important when you schedule your day to actually say when and in what order you are going to do things. A to do list on its own won't be enough.
If some tasks seem overwhelming just commit to 10 minutes of them. You'll find that you end up doing more than your allocated time, usually. Another technique is to switch tasks mid flow. So, if you avoid making a phonecall, for example, you can start doing a smaller easier task that requires less thought, such as putting the washing on, then immediately make that call.
There's lots of good tips on procrastination and motivation online.
When you plan your week, code each activity as an A (achievement), E (exercise) and P (pleasure), then after each activity, write a number out of 10 to rate each task in terms of how good you felt about it after you had done it. This helps build up a picture of what works for you. As a rule, use pleasurable activities as a reward for achieving things or doing exercise. It can be things like watching a TV show for a certain amount of time, reading a book, having a cup of coffee, reading a magazine, meeting a friend. Exercise doesn't have to be too arduous. It could be a walk to the post box, a bit of gardening, housework, swimming, yoga etc. Basically movement/keeping active.
I've been going through the same. I plan each week on a Monday morning. I've also taken up pottery, which I am thoroughly enjoying and it has really helped with my mood. Setting up activities can be really hard to start off with, esp when you have low mood and motivation. For example, everytime I tried to join a pottery class, I'd missed the start of term, or it was full, or I had to call back on a certain day etc, but forgot. For me, finishing off/sticking to tasks have been hard, so you might need to persevere a bit and come back to things another day/follow them up. But make sure that you're not putting them off or avoiding certain tasks.
I would definitely recommend doing something creative, such as a class or course. You definitely don't have to be creative to enjoy the process. It doesn't matter what the end result looks like, although you will notice that with practice, whatever you do,you will improve.
Hope this helps.