Mooncup/menstrual cup help?

You really need to give a little more information if you want help, for example what problems are you having and what do you mean by 'I just can't reach' - reach what? There's a cup with an applicator (Amycup) but it's pretty pointless, you don't need an applicator and just like with tampons an applicator makes insertion more difficult.

When you're tense vaginal muscles tense causing the vaginal walls to clench together - thus narrowing the vaginal walls and making it feel like it's stretching, so this is why it's hurting you. RELAX: take a big deep breath and relax your vaginal muscles prior to inserting, or try masturbating prior to insertion as when aroused the vagina will not only relax but also open, also consider why you might be tensing up - often it's just out of fear of using something new or worry about fear, remember that you are in control here so if it hurts then stop doing what is causing pain!

Menstrual cups can last for up to 10 years, they can be used at any point in your cycle and can be used in the bath or shower too...in short that means there's no rush, getting yourself frustrated trying to learn to insert it will work against you as when frustrated you're tense and if causing yourself pain you'll associate pain with cup use.