Most Helpful Guy
Unfortunately, some guys are just crap. Just as some women are crap.
Not every one cheats, male or female. A certain amount of caution is healthy, but automatically assuming that every person you date is going to cheat on you isn't. You can never have a meaningful relationship without trust.
The best thing you can do is be yourself, try to be happy, and make the most out of life. If it happens, then it is a terrible thing, but you can't let it destroy your faith in relationships.