Just found out my husband is bisexual after 20 years of marriage

I very recently found out that my husband is bisexual after 20 years of marriage and 3 beautiful children together. Needless to say we are both devastated but at this point determined to work out a stronger relationship as a result. He has confessed to exploring these feelings in the last couple of years with minor encounters with men which while they provided instant gratification, have left him feeling guilty and isolated. Our own sex life has been difficult for a while and now we are able to discuss why.... He has never spoken of this with anyone else and we are currently trying to reconnect and be open with eachother before contacting marriage support which we are very keen to do. We agree that we want to keep this private so unable to discuss with others so was hoping to connect with anyone who has experienced anything similar. I am running through every range of emotions which is exhausting but trying to be as strong and positive as I can. Any help would be appreciated....