From a Jain perspective, unhappiness (dukkha) arises mainly from our inner mental poisons (kashayas) and from actions that bind karma. Here are the main causes:

• Anger (krodha), attachment (raga), aversion (dwesa), pride (conceit), deceit (mada) and greed (lobh) — these mental states disturb peace and lead to suffering.
• Wrong understanding or ignorance (ajnana) about the true nature of self, others, and the world.
• Bondage of karma, caused by unrestrained thoughts, speech, and actions (himsa or violence, lying, stealing, sensual indulgence, and untruthfulness) that accumulate karmic residues.
• Excessive attachment to temporary pleasures, possessions, or ego prestige, which crumble and cause distress when they fade or are lost.
• Fear, insecurity, and suffering due to ignorance of impermanence (anicca) and the fundamental suffering of samsara.
• External circumstances that arise from one’s past karmas, such as ailments, aging, loss, and death, which are seen as part of the cycle of birth and death.

What helps in Jainism:

• Right faith (samyak darshan), right knowledge (samyak jnana), and right conduct (samyak charitra) — the three jewels that reduce and eventually dispel kashayas.
• Non-violence (ahimsa), truthfulness (satya), non-stealing, chastity, and non-possessiveness (aparigraha) in daily life (the five vows for lay followers; stricter for monks).
• Regular practices like meditation (samayik), self-purification (pratikraman), and regular reflection on one’s thoughts, speech, and actions.
• Cultivating detachment and understanding of impermanence to lessen craving and fear.

If you’d like, I can tailor this to whether you’re reading as a layperson or a monk, or point you to specific Jain practices that address these causes.