am I a bad mom?

So my son (he's only four months but he's pretty strong) fights me when it's time to eat. He kicks and screams and slaps (he doesn't know what he's doing) so I've resulted in laying next to him in bed and bottle feeding him. My boyfriends mom told me this was bad.. and I know it is.. but it's one of the only ways to get him to eat when he throws tantrums. Sometimes he will let me feed him if I hold him, but not when he's fussy. I took him for his four month well baby and the doctor saw me doing it today (she's been rude to me in the past) and really made me feel terrible. Does anyone else do it or have done it to their kids and they came out okay?