I'm not seeing any evidence he was suicidal. Self-immolation has been a form of protest since forever and has made a real difference at times.
en.wikipedia.org
en.wikipedia.org
en.wikipedia.org
Thích Quảng Đức (c.1897 – 11 June 1963) was a Vietnamese
Mahayana Buddhist monk who died by
self-immolation at a busy
Saigon road intersection on 11 June 1963.
[2] Quảng Đức was protesting against
the persecution of Buddhists by the
South Vietnamese government of
Ngô Đình Diệm, a staunch
Roman Catholic. Photographs of his self-immolation circulated around the world, drawing attention to the policies of the Diệm government.
John F. Kennedy said of one photograph, "No news picture in history has generated so much emotion around the world as that one".
[3] Malcolm Browne won the
World Press Photo of the Year for his photograph of the monk's death.
Quảng Đức's act increased international pressure on Diệm and led him to announce reforms with the intention of mollifying the Buddhists. However, the promised reforms were not implemented, leading to a deterioration in the dispute. As protests continued, the
ARVN Special Forces loyal to Diệm's brother,
Ngô Đình Nhu, launched
raids across South Vietnam on Buddhist
pagodas, seizing Quảng Đức's heart and causing deaths and widespread damage. Several Buddhist monks followed Quảng Đức's example, also immolating themselves. Eventually,
a US-backed coup toppled Diệm, who was
assassinated on 2 November 1963.
mondoweiss.net
