Real happiness and peace can be found in submitting to the commands of the Creator and the Sustainer of this world.  God has said in the Quran:
“Truly, in remembering God do hearts find rest.” (Quran 13:28)
On the other hand, the one who turns away from the Quran will have a life of hardship in this world.  God has said:
“But whoever turns away from the Quran,  he will have a hard life, and We will raise him up blind on the Day of Judgment.” (Quran 20:124)
This may explain why some people commit suicide while they enjoy the material comfort money can buy.  For example, look at Cat Stevens (now Yusuf Islam), formerly a famous pop singer who used to earn sometimes more than $150,000 a night.  After he converted to Islam, he found true happiness and peace, which he had not found in material success.