how can i go to sleep?

I would drink some warm, decaffeinated tea.
Your feet carry the most tension when you are awake, because they hold up your body. When your feet are completely relaxed, you can relax too.
Use some cream, but don't use an oily one, because it makes your skin slippery and it's not as easy to do a deep tissue massage. As for which cream to use, Banner Therapy has a therapeutic herbal muscle calm cream that is part of their organic skin care products.
It's a muscle mending lotion with essential oils and Capsicum, which is the heat-producing ingredient. In terms of really getting down into deep muscle and stimulating healing the Therapeutic Herbal Muscle Cream is pretty potent.
Spread it all around your feet, and squeeze your foot hard, and slowly slide your hands up, or down your foot. Keep doing this for a while. Then, use your fingers to press the middle of your foot, under your foot's pad. Keep massaging your foot, and when you think your foot is good and relaxed, move on to the next foot.

An herb that will help you become tired is (you won't believe this) catnip.
Breath it in, and you will become tired. I'm guessing you won't be trying that anytime soon, but if you ever wanted to try, here it is.

I hope I helped. I had sleeping issues too, and these do help.

Avoid bright lights,
Read
listen to calming music
drink warm milk

sleep at the same time and wake up at the same time
so your body clock will know when to sleep

do more sports

Always go to bed and wake up at the same time every day. try an over the counter sleep aid for a couple of nights to get you back into a regular sleep schedule. If that doesnt work, see your doctor and get a couple of prescription sleep pills.