@psalms91forme I don’t think your trainer’s advice of simply “eat more protein” is the best first move.
Yes, eating higher protein (if your protein intake is rather low) could be helpful for recovery and muscle growth, and satiety, but it wouldn’t be my first recommendation. I would guess your protein intake is not excessively low, but I could be wrong, only you can figure that out.
A dietary change is likely required to lose and maintain a lower body fat level.
I would suggest you take small incremental steps towards a health-promoting eating pattern. Eat more fruits and vegetables, whole grains, legumes. Incorporate nuts, and seeds regularly. Eat lean meats, fish, and plant sources of protein. Limit saturated fat from animal sources. Limit added sugars. Limit sugar- sweetened beverages.
To the extent you can make your diet more like this, weight loss and weight maintenance at a healthy body weight will become easier. You don’t have to be perfect, and you don’t have to do this all at once.
Exercise although extremely important for a whole host of reasons, is not a very powerful tool for weight loss. No where near as critical as diet. If you’re curious as to why, check out the book “Burn” by Herman Pontzer.
Good luck.