Seeking Sincere Islamic Advice and Support

Assalamu Alaikum, I’m an 18-year-old Muslimah, raised in a traditional Muslim family here in the Middle East. Lately, I’ve been struggling deeply with my faith, and it’s been really hard even though I try to stay on the right path. I’m not exactly sure when this struggle began because I’ve been praying and wearing hijab since I was young. But around the age of 14 or 15, I started missing prayers, delaying them, or forgetting them altogether, which I know isn’t right. Sometimes I’d pray only when someone reminded me or asked me to. I’d read Quran daily for school, but not out of my own desire. I kept my hijab on, though. Then I fell into some sins-like watching forbidden content and self-indulgence-and I did these things without much thought for a few months, which I deeply regret. When my parents found out, I tried really hard to stop, but controlling my desires has been tough. Sometimes I’d slip again just to feel some relief. Alhamdulillah, my fiancé is very religious and pious, and meeting him inspired me to change for the better. Since our conversation, I’ve been praying all five prayers without hesitation and even started wearing niqab and gloves to show my commitment and sincerity. I repent to Allah every night like never before. But the struggle with my desires continues; I fall into those sins again and again, each time filled with guilt and turning back to Allah with tears and duas. My fiancé has been so understanding. When I told him about my mistakes, he reminded me that Allah is Most Merciful and that we all make mistakes. His words give me hope, but still, I’m scared of failing again. I keep repenting, and sometimes weeks or months pass before I slip again, but I’m tired of this cycle. I wonder if I’m truly deserving of such a righteous husband given my struggles. Am I wrong for repeatedly making mistakes yet always returning to Allah? I really need advice and guidance on how to strengthen my faith and control my desires. I love my fiancé dearly, and he loves me too, but I fear I’m not good enough for him. What steps should I take to improve and find peace?