There are no publish guidelines on what would be considered good reason to allow a person to keep their EU FAM.
What has been seen in past posts on this forum is that ISD officer are quite "by the book" on these situations and will check the minimum requirements to allow for the applicant's retention of Stamp 4EUFAM, which from what you said so far you don't seem to fit minimums:
A. Divorce or annulment of marriage
To retain a right of residence after divorce or annulment of marriage or annulment or dissolution
of a civil partnership under Regulation 10 of the Regulations of 2015 an applicant must meet one
of the following criteria.
i. Prior to initiation of the divorce, annulment or dissolution proceedings, the marriage or recognised civil partnership lasted at least three years, including one year in the State, and the EEA national was exercising their EU Treaty Rights in the State at the time that the decree of divorce, annulment or dissolution was made.
ii. The applicant must have custody of the EEA national’s children by agreement between the applicant and the EEA national, or by court order.
iii. The applicant has the right of access to a minor child, provided that the court has ruled that such access must be in the State and for as long as is required.
iv. The retention of such right of residence is warranted by particularly difficult circumstances, such as the applicant having been a victim of domestic violence while the marriage or civil partnership was subsisting.
B. Death of the EEA national
To retain a right of residence under Regulation 9 of the Regulations of 2015 after the death of the EEA national, an applicant must meet the following criteria.
i. The applicant must have resided in the State with the EEA national for at least one year prior to the death of the EEA national, and
ii. The applicant must be employed or self-employed in the State, or possesses sufficient resources to support himself or herself and any dependants
OR
iii. If the EEA national’s children, being resident in the State, are enrolled in an educational establishment in the State for the principal purpose of following a course of study there, then the children and the parent who has actual custody of the children will be entitled to reside in the State until the completion of the course of study.
C. Departure of the EEA national from the State
Where the EEA national has left the State and his or her children, being resident in the State, are enrolled in an educational establishment in the State for the principal purpose of following a course of study there, then the children and the parent who has actual custody of the children will be entitled to reside in the State until the completion of the course of study.
The reality is that you need to inform the immigration office about your change in situation, and perhaps check with a solicitor on your options.
The immigration office carries routine checks which would be able to flag that your former spouse no longer lives in the country, or at the same home as you, which would trigger an evaluation of your current permission to be in Ireland.
