Relax! You should first try not to pump out the milk to see how much you have. Please note that the quanitity that you can pump out doesn't equal to the milk you actually can produce. Your baby is much better than the pump in getting the milk out from your breast. Just keep on letting your baby suck your nipple on a regular basis (every 3 hours). Don't cry! Too much pressure will affect milk supply!!!!
I want to share my experience with you. I have 2 daughters and both of them were breast-fed until they were 1 year old. I did not feed them with any milk powder until they were 6 months.
I went through very difficult time as what you mentioned.
When my first daughter was 4 days old (just came home from hospital), I breast -fed her every two hours. But She started to cry non-stop. I breast-fed her again, but she refused my nipple. She did not want to suck my nipple. I was so disappointed. However, I insisted on not to give her any milk powder. I waited and tried until she was really very very hungry. Then, she started to suck my nipple for milk. My daughter also cried overnight and woke my husband up for about 1 month. I kept feeding her during the nights and just slept for few hours every day (but broken sleep). After 1 month, things suddenly went better. I found that I had more milk and she was used to sucking my nipple for milk more regularly (say every two to three hours).
During that difficult time, I cried and was not sure whether I should insist on breastfeeding. My husband gave me tremendous support and told me that breast milk was the best food and the best gift for babies. Three months later, everything was very smooth. I enjoyed breastfeeding my babies and hugging my babies tight.
Hope you can get the fun of breastfeeding.