You do what is best for you and totally ignored this man. My ex used to put a downer on my achievements and if I was you I’d put a great distance between you and this man. Well done you. Enjoy your success. Buddha quote “do not let the behaviour of others destroy your inner peace” Work, achieve, fulfil and enjoy your life. It’s a big achievement under the current circumstances to find employment. If he cared he would be happy for you and encourage your success.