Has the Gympie Gympie tree driven humans to commit suicide because of the pain from its sting?

Question

I often see the Gympie Gympie mentioned in fun facts or as an answer to "what are the scariest plants in the world?" or "What's the worst pain?"

The plant is covered in stinging hairs that once touched can inflict pain that lasts for years. One time a guy used it as toilet paper by accident and killed himself because the pain was too strong.

My only source for this information is an article by the Australian Geographic called Gympie Gympie: Once stung, never forgotten and an article called Being Stung by the Gympie Gympie Tree Is the Worst Kind of Pain You Can Imagine by Oddity Central. However, the Oddity Central article is very similar and it uses the Australian Geographic article as its source.

The article(s) states:

Cyril Bromley described falling into a stinging tree during military training on the tableland in World War II. Strapped to a hospital bed for three weeks and administered all manner of unsuccessful treatments, he was sent “as mad as a cut snake” by the pain. Cyril also told of an officer shooting himself after using a stinging-tree leaf for “toilet purposes”.

And also:

[ ... ] tales abound in local folklore of horses jumping in agony off cliffs and forestry workers drinking themselves silly to dull the intractable pain.

1. Can the pain last for years?

This seems to be the case as Earnie Rider claims "The stinging persisted for two years and recurred every time I had a cold shower." This is my only source.

2. Have animals (such as horses) been known to kill themselves in agony?
3. Have humans committed suicide due to the pain?

Answer 1

Gympie-Gympie is said to have the most painful sting of any plant in Australia with reference to this source.

1. Can the pain last for years?

Answer: Partly yes up to one year referring to research by Marina Hurley in 2000. The stinging sensation can be felt up to a year since human bodies cannot break down silicon.

The hairs are often so small that the skin closes over them, and any contact or hot or cold temperatures on the site can be painful for up to a year after the initial sting (Hurley, 2000) Source: Dendrocnide the Stinging Trees

2. Have animals (such as horses) been known to kill themselves in agony?

Answer: Partly no since the reaction might vary from mild irritation to death in different species. The reaction depends on the species of animal that gets stung, and the number of hair which get stuck in the skin. Many native mammals and birds are also noted to be not affected by the stinging hairs.

The sting of Dendrocnide is far worse than any species of Urtica ("Contact Urticaria"); they have been known to kill dogs and horses that have bumped into them, and there are stories of human fatalities, but with only one official death (Hurley, 2000) (Everist, 732) Source: Dendrocnide the Stinging Trees

Horses have been known to be killed by such reactions which is described here.

3. Have humans committed suicide due to the pain?

Answer: There are no recorded instances of humans committing suicide due to the pain but there are anecdotes of people killing themselves which are not backed by authentic sources. Also it should be noted that there is no tissue damage and the toxin is not known to be fatal.

The Dutch Botanist H. J. Winkler made the only official recording of Death By Stinging Tree, for a human. It was in New Guinea, back in the early 1920s. There have been other anecdotal stories from soldiers in WW II suffering intense pain, and of an officer shooting himself because of the unrelenting pain - but these are just word-of-mouth. Source: Stinging Trees

A military officer supposedly shot himself to be rid of the pain of the sting, and another had to be restrained in his hospital bed for three weeks (Hurley, 2000)