Those exams are really not my favorite thing either! However, I do have some suggestions to make it easier on yourself.
Your doctor is a professional. They go through several steps to make sure to remove any sort of intimacy in the situation. For example: the doctor will leave the room when you undress so you don't feel as if you are stripping for him or her; they will not tell you to "spread your legs," they are more likely to say "please part your knees," which is less sexually explicit.
Remember that this doctor has probably done the exam hundreds or thousands of times before - they have seen everything! They are not turned on or off by your anatomy, nor will they be disgusted by it.
When you go to the exam, I highly recommend that you tell the doctor that the last time you went you had a bad experience and how it made you feel (angry, embarassed, etc). Explain that this is basically your first exam and you are nervous. For my first exam, the doctor said she would be very gentle and would open the speculum as little as possible (i was a virgin).
If you have certain questions you would like to ask, write them down before you go. That way you won't be worried about remembering to ask them. These doctors have also heard everything, so don't be embarassed about any questions you may have.
Additionally, the two doctors I have gone to have always explained what they are going to do before they do it ("i'm going to insert the speculum, it may feel cold at first," etc). This prevents any surprises!
Personally, I do not find pap smears painful at all. Try to remain relaxed and that will make it easier. Concentrate on slow, even breaths to help you relax.
My doctors have also done everything they can to make me feel comfortable. They are pretty good at being able to tell if you are nervous or not. They may make a little joke to try to get you to laugh - even during the exam! The last time, my doctor began a conversation with me before the exam started. She had asked the usual questions about health history, and then proceeded to ask about my school or work or my life in general while we both prepared for the exam. She continued this conversation during the exam, and it kind of keeps your mind occupied.
Sorry this is so long, but I hope some of this helped! I bet your doctor will be very understanding, especially if you mention that you had a bad experience.