The Buddha knew this was a particularly difficult sense pleasure to overcome an attachment to, which is why this isn't a pārājika; as you attempt to keep your vow of celibacy it is important to be realistic about the difficulties that will arise. This compassion for yourself while you undertake this vow is very important. On a related note, it is one thing to abide by the injunction to not partake of sexual pleasure, but the goal is not the practice so much as to see it with Right View for what it is: just one more attachment to form. Once this is experienced first hand (
), celibacy becomes a peaceful abiding here and now.
I also think it is important to realize that celibacy is easier to the extent that you aren't subjecting your senses to things like advertisements and standard television, because they usually contain some sexual imagery of one sort or another and what seem like minor examples now will, for a time, become VERY salient and bothersome. In my direct experience, the precepts against entertainments, shows, and perfumes really helps as separating oneself from those things often also creates a felt
sense of seclusion from such distractions which can be very beneficial.