2. You'll not be tested with more than that you can bear.
3. In everything that happens to us, there is a hikmah (a good reason with good outcome, a blessing if you persevere). The hikmah may be apparent and realised soon, or much later in life, or you may not realise it at all, if you are not observant and grateful.
4. As a Muslim, trusting God and His plans, leaving the outcome to Him after putting our effort, is essential. Muslims would be familiar with "tawakkaltu 3alallaah" - In God I put my trust.
5. We are not alone, especially when in suffering, God hears our calls. God is closer to us than our jugular veins.
Darks days are moments, dark thoughts appear in moments, and moments will pass.
Even suicidal thoughts appear in moments, hang on for a while and let those moments pass.
Put your trust in God.
p.s. Even practising Muslims, may in the spur of the moment, while in despair, forget about Allaah's mercy. That's where reading back, or reminders from good sincere friends come in handy. May we be under Allaah's care and guidance always.