Letting Go of a Haram Attachment for Allah’s Sake: Need Advice

Salam, I’m reaching out for heartfelt advice from anyone who’s been in a similar spot. I’m in a relationship that’s not halal, and I’ve grown really close to this person. It’s been about a year now, and honestly, from the start, my intention was to make it halal. I kept bringing up marriage, and he’d always reassure me, saying we’d tie the knot soon. Initially, my family wasn’t on board with me talking to a man. I approached them about wanting to get married, but they insisted I finish university first, even though I explained the situation. They identify as Muslim but aren’t really practicing, so I’m the only one striving to follow Islam at home, which makes things tough. My sister-who was my absolute best friend and my whole world-also disapproved and told me to end it, but by that time, I was already emotionally invested. Then my world shattered: my sister passed away. It was the hardest test Allah has ever given me. My faith hit rock bottom, but I clung to my prayers and the Qur’an as best I could. During that dark period, he was my support. I leaned on him heavily, and he kind of filled the void my sister left. That’s made me even more attached and grateful, so walking away feels impossible. The real problem is our faith levels don’t match. Early on, he seemed to practice, but later I saw he’s only Muslim by title. He doesn’t observe Islam, commits shirk by worshiping other entities, and even has negative opinions about our deen. I’m working hard on my own iman. I keep up with my five daily prayers, wear hijab, try to do extra sunnah and tahajjud, and read Qur’an regularly. It took me a lot to get here, and I’m scared of losing this progress. I kept hoping I could guide him, since Allah guided me, but it’s been over a year with no change. I now realize only Allah gives guidance, and I can’t change anyone-even the prophets couldn’t guide their own family members, so who am I? Deep down, I know I must leave this for Allah’s sake because it’s haram and there’s no blessing in it. But it’s painful: I love him and I’m so attached. I’m also terrified of being alone. My sister was my only confidant, and losing her left me isolated. He became my person, my source of comfort. He has good qualities, but I can’t compromise on Islam. I don’t want to backslide after coming this far, and I can’t imagine a future where my children aren’t raised with strong Islamic values. For those who’ve left a relationship for Allah: How did you muster the strength to end it? What kept you busy and helped with the loneliness? How did you cope with the heartache and attachment? Did Allah grant you something better in return? Please keep me in your duas. I just want to do what’s right for Allah, even though it’s so, so hard.