Oh, please stop crying! Pick yourself up and get a plan.
First of all, is there fluoride in your drinking water? You need to supplement if you don't. If you have well water, if you use bottled water at home, if your municipality doesn't fluorinate, your child needs fluoride supplements. It makes a huge difference. Find out now and start the supplements.
What is your evening routine with her? Does she eat before she goes to bed? Does she breastfeed still or have a bottle? Do you brush her teeth before bedtime? Does she feed in the middle of the night?
You need to make sure her teeth are brushed before bedtime and no more feeding in the middle of the night. Make a game with the brushing. You don't want there to be a fight over it.
Finally, is this a pediatric dentist? If not, you need to go to a pediatric dentist. My own children had laughing gas and did well on it. My younger one slept through removing two baby teeth. My older son was very stressed out, and it helped him manage. I would say that unless these teeth really have to be drilled on, I would wait until she is older. I'd also find out, again from a ped dentist, if you can have sealants put on her other molars before there are any visible cavities. Along with fluoride, sealants make a great difference.
People of my generation got cavities starting young and we all have mouths full of dental work. When they figured out fluoride (the safe kind, not the kind that anti-fluoride people try to scare everyone with and should be discounted), dentistry started to change a lot. Instead of filling cavities all day long, dentists started learning ways to do cosmetic dentistry. My younger son didn't have a cavity until he was in college. It took a long time for the dentist to decide to fill it, it was so slight. This is thanks to the fluoride supplements I gave him until he was 12 years old. My older son had 4 baby molars with very little enamel, soft molars, which the doctor said could have been caused by a high fever when he was a tiny baby. They were so soft that sealant couldn't even stick to them. Fluoride couldn't help them. We just had to fill those teeth until the permanent ones came in. And in his 20's, he STILL doesn't have any fillings.
Some people do have poor genetics where cavities are concerned, but how you deal with feeding issues, brushing and fluoride, along with twice a year cleanings will make a huge difference in your child's dental health. Now find out about your fluoride situation, about sealants. If you don't have a ped dentist, find one. Write down questions - don't be so upset that you forget to find out if the dentist saw the cavities on an xray. Ask to see those cavities. This is just one of many things a doctor will give you not-so-good-news about. It's important to manage your fears and move ahead, not only for your sake, but for your child's sake. It can be the difference between her getting through a procedure without fear and her having a huge meltdown.