Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concern..
As per your complain it seems that the large ulcer is n Apthous ulcer and the cause for it seems to be any
allergic reaction that is leading to swelling of the lip too..
As the area of the ulcer has got severely inflamed there is swelling of the lip too..
I would suggest you take anti allergic like
Benadryl or Levocetrizine for reducing swelling..
Take anti-inflammatory painkiller like
Ibuprofen to reduce pain and inflammation..
You can apply a numbing gel containing Lignocaine over the ulcer for relieving pain..
You can suck ice and do cool water rinses for relieving inflammation..
Do cool compresses over the lip..
Maintain a good
oral hygiene..
In case if there is no improvement in a week consult an Oral Physician and get evaluated..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora..