Why do my wishes not come true except after severe hardship, and is this due to sins I have committed despite frequently engaging in dhikr, istighfar, and tasbih?

A Muslim should be keen on what benefits him, strive to achieve it through legitimate means, seek Allah's help, not despair, and be content with Allah's decree if something he dislikes occurs. Steadfastness in obedience and piety, and avoidance of sins are among the most successful means to achieve what is desired, as Allah Almighty says: "And whoever fears Allah - He will make for him a way out, and will provide for him from where he does not expect." One must persevere in acts of obedience, seek forgiveness, and supplicate; for Allah Almighty says: "And your Lord says, 'Call upon Me; I will respond to you.'" And one must have a good opinion of Allah; for in the Hadith Qudsi: "I am as My servant thinks of Me. If he thinks good of Me, then good will be for him; and if he thinks evil of Me, then evil will be for him."