I go to acupuncture several times a week. I've been doing it for my eye for 6 mo, and also did it for a year or two about 5 years ago for shoulder pain. It is one of the only things that gets me through the week right now. Acupuncture doesn't help me as much as I would like it to, nor do the effects last as long as I would like, but it DOES help, and as you said, as long as it alleviates some of the pain... But, it is a very personal experience. Some people respond really well, really fast, others do not. It's all about how your body reacts. Mine is very stubborn, so within several sessions of finding a treatment that works well, my body adjusts & we have to rethink our approach.
If this is your first session ever, I would definitely eat something before you go. Acupuncture moves a lot of energy around (sometimes you can even feel it, it's really neat), and it can make you feel shaky during/afterwards, especially in the beginning. Also drink a lot of water for the next day after going, as it will help eliminate the "negative chi" in your body that was stirred up by the treatment.
Also, don't be disappointed if you don't get any results the first time, or even the first couple of times. It takes time for the acupuncturist to understand your condition & find the points that your body will respond to. If you can, stick with it for a month or two before you decide whether or not it is helping & it is something that you want to continue.
And if you are scared of the needles, ask the acupuncturist to stick one in your arm or something (a random place not associated with your pain) before he does the actual needling so that you can see what it feels like, believe me, it will make you much more confident & relaxed to see how tiny the needles are & what it feels like. Yes, some points hurt, but others you can hardly feel, it depends on the point. And when the do hurt, it is only during the initial insertion, so it just lasts a few seconds to a couple minutes. And if your acupuncturist is good, he'll start you off slow so that you can build up trust in him first. I've gotten to the point where I let my acupuncturist do anything on me, because I trust him so much. He does points on me that almost no one else can tolerate, but if you like & trust your acupuncturist & know that it will help, it is worth the momentary pain in the long run.
Good luck! I hope it helps! Let us know how it goes!