Я думаю, что решением вашей проблемы является не чтение книги вероятностей, а чтение большего количества статей в TCS.
Most papers in TCS don't actually use very advanced probability tools. Most of them use a small collection of basic and well known probability tricks. The reason you have a hard time following them is that you are not yet familiar with this bag of tricks, and many of those papers don't bother to explain these tricks because they assume the reader knows them. Some of those tricks are not taught in most probability books, at least not in the specific form they are used in TCS papers.
Another reason is that TCS papers use a slightly different terminology than the one taught in basic probability courses - e.g., in TCS papers a random variable can usually take values in {0,1}n, while usually in probability courses random variables are defined as taking real values.
So, by reading more TCS papers, you will get more familiar with the bag of common tricks and with the terminology, and and with time they will be easier to understand.
That said, reading a book on probability is always a good idea. Among the books suggested above, I am only familiar with "Probability and Computing: Randomized Algorithms and Probabilistic Analysis" of Mitzenmacher and Upfal, and it is a very good read - in particular, it will help you get familiar with the some of the terminology and tricks used in TCS.