What are the effects of Botox like?

One day, the flesh under my ears and below my jaw started bulging out, so I thought I had just gained weight. However, when I went to the hospital, I was told it was salivary gland hypertrophy. Because my parotid glands are swollen excessively, my jawline has collapsed, and my face looks round and large overall, causing me great stress every time I look in the mirror. I have heard that Botox is an excellent treatment for reducing salivary gland size, and I am wondering if the injection really causes the bulging flesh under my ears to flatten out. I am also worried about potential side effects, such as extreme dryness in the mouth or discomfort when chewing food due to reduced saliva production. I am writing this post to hear firsthand accounts and learn about the level of pain experienced by those who have successfully corrected facial asymmetry by injecting Botox directly into the salivary gland area.