Common Variable Immunodeficiency Support Group
Common variable immunodeficiency (CVID) is a group of 20-30 primary immunodeficiencies (PIDs) which have a common set of symptoms but with different underlying causes. CVID's underlying causes are different, but the result of these are that the body doesn't produce sufficient antibodies in response to exposure to pathogens.
I think they would put you in the cvid bucket.
I was diagnosed a year ago at 38. Low IGG and poor vaccine response
It is a long process- keep doing research- note your symptoms etc- and make sure you are with a competent- truly qualified doc.
Good Luck.