No.... don't just randomly eat fat to lose weight.
If I were you, I'd try Whole 30 which disallows the "treats". It's only a month. You learn a lot about yourself and eating habits. The treats are probably what are making you gain. The calorie counts in those things get high fast. On occasion, I have a mug cake. That cake has something like 400 calories in it! Yeah, it's good... but no it is too calorie dense to be anything but a treat. People complain about fruit.... but how is a 400 calorie mug cake better than a 100 calorie banana for dessert in terms of weight loss (if you are not someone that just can't have fruit)?
The next thing is to not view fat as something you can just chow down on. Yeah, put butter on your veggies. But use some sense. It isn't a low fat diet, but eating spoonfuls of fat will make you fat unless it is replacing other calories.
Lastly, eat more protein.