You are right, about this, if you lose your gambit, you could end up losing your job and you could also end up having the board vote to do exactly as you are afraid.
The members of the board of directors have a fiduciary responsibility to the non-profit members to exercise due care in performing their duties, and to act reasonably and in good faith in accord with the best interests of the non-profit. As a member, you can sue the board member for a breach of fiduciary duty
in not following the requirements in the by-laws regarding meetings.
Essentially, you may file the suit on behalf of the company against the offending board members. The procedures for doing this are very complex and are outside of the scope of this website. Suffice it to say, you need to hire a local lawyer who does business and corporate litigation
and inquire about bringing a shareholder derivative suit against the other board members. That lawyer will need to sit down with you and examine all the documents and evidences you have of violations of the by-laws by the other members, and provide you with a full assessment as to whether you have a strong enough case to merit the action.
IN regard to the board firing you, do you have a written employment contract
as the CEO?