Hi.
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns...
As per your complain it seems that your son is who is 22 months old is suffering from HERPATIC 
GINGIVOSTOMATITIS which is a viral infection and can lead to fever, 
swollen gums and bleeding and inflamed gums..
The initial treatment is directed towards reducing fever and decreasing the discomfort caused due to inflammation in mouth..
You should feed your son with a soft ,cold and bland diet, a low spice vegetable soup, flavoured gelatin, bread socked in milk etc can be given..
Avoid citrus juices like orange juice and can give him fresh apple juice..
For fever you can give him 
Tylenol or 
Acetaminophen ..
Application of a numbing gel like Lignocaine over the gums and other sore areas of mouth can provide relief, but care should be taken not to involve large areas of mouth as when being numb the child can accidentally bite the tongue and also damage other areas of mouth unknowingly..
Sucking ice pops or a frozen apple juice popscicle can help in reducing inflammation and discomfort...
Maintain a good 
oral hygiene and use an ultra soft toothbrush for brushing can help by preventing trauma and pain to gums..
In case if there is an outbreak of sores or blisters 
antiviral medicines like 
Acyclovir can be advised by a Paediatrician to reduce the duration of the disease and prevent further outbreaks..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora..