I have actually made a sort list on this blog a few times. But since I anyway have trouble identifying what exactly are my sins, I fall back to another statement of the sages. פישפש ולא מצא יתלה בביטול תורה One who has troubles should examine his deeds. One has examined his deeds and not found anything, should attribute the problems to lack of learning Torah.
[Essentially my sins seems to be leaving the straight path of Litvak Torah. I.e. the Gra's path.]
In any case what I think are the major causes of sin are that people join cults, and then their whole world view changes. Straight Torah no longer holds the charm it once did for people that join cults.
And the entire religious world is basically a large bunch of cults. Even though they all claim Torah, there sadlly is little in the religious world that is kosher in any sense of the word.
[The major issues for me are certainly Bitul Torah. For even when I got to Israel which was a great step up, I slacked off in learning Torah. I also did leave Israel eventually which I think was a terrible sin.]
[This is not intended to disparage kosher places built on straight Torah like the yeshivas that go by the Gra. The trouble is straight simple Torah is hard to hold onto.]