How to cope after a long term relationship ends? Myself F 29 and partner M 29

I’m F 29 a few days ago my partner of 9 years M29 ended our relationship we were engaged and now I feel hopeless. To me it’s come out of the blue we went away for the weekend and had a great time and he blinded sided me on the Monday evening saying he’s sorry but he’s been hiding part of himself and he also attracted to men and he can’t keep hiding it and needs to experience that side of him. It keeps making him depressed and he can’t carry on. He says he loves me but the 10% of him keeps coming back and he needs to explore. We have a house and a dog and I feel so alone I don’t know how to cope. I’m normally someone who is always happy but I feel so low and don’t know what to do with myself. I want him to be happy but honestly I feel like I have been thrown away and that 9 years of being together means nothing. I know he’s already on dating app so it just makes it worse but he keeps saying he loves me so I feel stuck and useless. I know he didn’t mean to hurt me and he’s hurting just as much but I feel I got the worse end of it.