find myself again

I have a really good job which I enjoy I feel I had to change my personality to fit in with the job and get the results they wanted from me which I have done, work is going well and i’m hitting the targets I need, this is good but my boyfriend is saying i’m less and less like the person he met i’m doing the job for us both to get better things.I know i have changed a bit but i didn’t think as much as he makes out.i;m sure he’s telling me to help me but it just makes me feel worse and really really sad, am I such an awful person now? Is it all my fault? sometimes I cant be bothered with it all I try my best to be the person he met as I did like myself then, all he says now is i’m ot like I used to be but on days when I do try he will menton it too I wonder will I ever get back there?