Nearly crossed the line - how do I move on?

Assalamu alaikum. I’m a 21M who used to be known as a pretty practising Muslim - no music, praying even when it was tough, someone people trusted for religious advice. Over time I drifted and started having intellectual doubts about the deen that chipped away at my iman. I still keep up the wajib acts and avoid major sins, but I’m not where I used to be spiritually. About a month ago I met a Muslim sister (20F) and we hung out three times. Once we were in her room just talking and I honestly didn’t expect anything to happen. But one thing led to another and she ended up on top of me, grinding. I realized what was happening and stopped it - clothes stayed on, no kissing, no penetration. We both just froze, then started crying when we understood how close we’d come. I’m crushed with guilt. I don’t know how to move forward. I’m not even sure she’s someone I’d marry. What was I thinking? It wasn’t worth it. Do I have a past now that will make it harder to find a spouse? How should I make amends and rebuild myself? I feel so ashamed and disgusted with myself. JazakAllah khair for any advice. I’d appreciate practical steps for repentance (tawbah), repairing my relationship with Allah, and how to handle the possibility of marriage after something like this. Please keep the suggestions grounded and realistic.