Basically you need to experiment with what is sustainable for you.
It may well help to journal, online or on paper, write down what you eat, what you do and how you feel. Then you'll be able to look back and see what you can tweek.
You may need to go very low carb, you may need to go higher carb and lower fat, you may need to allow yourself one day a week off plan, you may need to be really strict and aim for 100% compliance, you may need to do leptin reset, you may need to count calories to get handle on portion control. You may need to meal plan for the whole week so you know exactly what you are going to eat and when.
You can work this out after you figure out where you are at now by journalling.
Oh and weight loss is 90% what you eat, if swimming makes you eat more than you burn off then don't do it, or work out how much you burn off swimming and don't eat back more
You know all those pictures of Adam and Eve where they have belly button? Think about it..................... take as long as you need........................