Everything is falling apart

This is going to be long, sorry!

Ive been married over15 years. Most of my marriage has been stable and happy but we are more like friends. There is almost no sexuality and it has been like that the entirety of the marriage. About 5 yrs ago my husband started struggling w and addiction to alcohol. Lying about drinking, hiding alcohol, driving drunk..all regular occurances. He is also deeply unplesant when he drinks. Often starting petty arguements that he will not let go. This has been really rough on my self esteem as I feel completely unseen and undesired. Alcohol and food are his priorities.

last year I had a major mental break. I became stuck in a 24/7 depersonalized state. I could barely function or leave the house. Because of covid I lost my job. I didnt and still dont feel like myself at all. I feel like a completely different person. Disconnected emotionally from everyone. So I started spending all if my time online, much of it in chat rooms. I felt more real and alive online than in life. I met someone that I became deeply drawn to. I knew it was wrong but I engaged in sensual chats anyways. As terrible as it sounds it made me feel something..instead of nothing. This situation was toxic and I did cut it off months ago but now I feel crushing emptiness. Im worried I dont feel enough shame about it, and that i will never feel things for my husband again. I feel crazy. Is my marriage doomed?