Isn't dw i gwneud in the present?
In general this sentence has a few mistakes. If it is meant to be present tense then it would need an "'n" after the "i". But I am certain that it should be past in which case it should be "Yn y gorffennol, dwi wedi gwneud swyddi da".
That's what I put. Maybe I am beginning to get the hang of this.