即使 + a situation which is not a fact + 也.....,即使.....也...is to show how determined you are, or how hard it is to change the situation.
1. 即使雨很大,我也要去跑步。 Even it's raining heavily(which is not the fact), I'm going to run.-----to show how strong will you have for running.
2.如果你平时不学习, 即使你今天学24个小时,明天你也不能通过考试。If you don't study normally, even you study for 24 hours today(which is not the fact),you are not going to pass exam tomorrow.---to show how hard it is to change the situation.
虽然 + fact + 但是.... Means you know the fact, but still you hold another opinion.
1.虽然雨很大,但是我要去跑步。 Although it's raining heavily now,I'm going outside to run.
2.虽然我平时不学习,但是我今天学习24个小时,明天一定能通过考试。 Although I didn't study usually, I will study 24 hours today, and I believe I will definitely pass the exam tomorrow.
If you have any questions,welcome to message me ,and it would be better if you try to write another 2 sentences with these 虽然/即使,I will help you to check it.