The Short answer to this question is "Maybe".
Not very helpful, but hear me out.
The requirement for the person inspecting safety harnesses, and height safety equipment, is that they are "competent".
So the real question then becomes, Am I Competent?
Now to answer that we need a definition of what "competent" is in relation to inspecting harnesses and height safety equipment.
Competence is combination of qualifications and experience. So with that definition, experience alone, is not enough to be deemed competent. Also qualifications alone don't make you competent.
Now we can answer the question of "can I inspect my own harness?" with a resounding YES if you have both a qualification and you are experienced in inspecting