So you've already done the most important thing: prioritize the things you need/want to do. You say you have 4-5 months in which you have to cover 4 subjects. That's your list. Four things. Nothing else.
If the topics are roughly of the same difficulty, divide it up in to 5 weeks each, and that's it. When the time's up, move on. If you need to, you can move back and forth between the 4 topics for a little variety, but remember context switching does come with a cost.
It would probably be helpful to list all the other things you want to do, but can't, as a way of reinforcing to yourself that for the next 5 months, you're not doing those things. You can pick up on that list afterward... but when you do, make sure you keep up the same discipline: pick a few topics, decide to do them and devote focused time to them, and decide to leave the others on the list and not do them until you've finished with your current working set.
It's really hard to let go of a lot of things that we want to do and learn. I experience this pretty often, too, and I'll admit I'm not always good at following the above advice. But you have to be realistic about the quantity of time you have. Deciding what to do also means deciding what not to do, which is just as important.
If the topics are roughly of the same difficulty, divide it up in to 5 weeks each, and that's it. When the time's up, move on. If you need to, you can move back and forth between the 4 topics for a little variety, but remember context switching does come with a cost.
It would probably be helpful to list all the other things you want to do, but can't, as a way of reinforcing to yourself that for the next 5 months, you're not doing those things. You can pick up on that list afterward... but when you do, make sure you keep up the same discipline: pick a few topics, decide to do them and devote focused time to them, and decide to leave the others on the list and not do them until you've finished with your current working set.
It's really hard to let go of a lot of things that we want to do and learn. I experience this pretty often, too, and I'll admit I'm not always good at following the above advice. But you have to be realistic about the quantity of time you have. Deciding what to do also means deciding what not to do, which is just as important.