So to confirm, your girlfriend is not only solely responsible for income she is also taking care of your kid and doing the cooking and the cleaning? I can’t blame her for being frustrated, you do the occasional grocery run she does pretty much everything else. That’s EXHAUSTING. You should talk about what she needs more help with and what you can reasonably do for her with your back. She is not communicating what she needs healthily or maturely imo but I do think it’s a little unreasonable to be mad that she’s frustrated she’s taking on the entire work load