She is just going thorugh the terrible 2!!!! do not worry and try to be patient..it will be over soon....!!
Does she speak at all? Will she come when you call her name? Is everything inflexible - from your travel routes to where one sits at the dinner table? Is she obsessed with one or two items rather than playing with several different toys? Will she respond favourably to another child? Do loud noises scare her? Is she content being alone? Do you feel that she is capable of "thinking"? Just some questions ...
Our nephew was diagnosed with high-functioning autism several years ago and the above were many of the items he had trouble with during the toddler years.
It is hard to tell what is going on from your description. She seems to be understanding you which means her receptive speech is good so that if she IS on the spectrum, she is on the high functioning end. I think if she is not speaking and you are concerned, I'd consult your pediatrician. Perhaps a visit to a developmental specialist would be a good idea just to illeviate your concerns. Did she meet her developmental milestones? Some children are tempermental and do cry easily and often and some (like my son) have sensory issues that cause their emotions to be unregulated. My son also has a terrible time self soothing once he is upset. Children with speech delays are often volatile as they become very frustrated as they can't communicate. I think it is time to call your doctor. There is so much you can these days through early intervention to help your child. good luck