Hi,
I am a big fan of whey protein. It is an easy method for ingesting protein if you do not have time during your day to prepare meals. People will say "make an effort and cook", generally people who say this have some spare time on their hands and I dont.
I can only tell you what is working for me, people will give you different opinions and quote stuff they have read but this is what I am doing.
Started at 223lbs age 30 5ft 11"
Currently 198lbs
Time since I started losing weight - couple of months.
I have completely cut out all processed foods, except the whey protein powder

I only eat food that I prepare myself. At the moment this is mainly frozen bananas and other fruits blended in to a smoothie with some protein powder.
At the weekends I eat and drink whatever I want.
Exercise - I walk/run 5 miles most nights. If you want to lose weight you must burn more calories than you are taking in. I am focused on mostly cardio work at the moment. When I have hit my target weight I will concentrate on building muscle.
If you do too much muscle building you run the risk of creating big muscles under fat and that just makes you look even bigger. I am losing the fat and then building the muscle.
I am doing some strength training, mainly working on a pull-up bar. My chest is noticeably more defined and fat is quickly vanishing. My back and neck are getting some definition. I am certainly at a calorie deficit and am shedding fat but I am most certainly building strength and muscle. I am quite sure I am not eating at an optimal level to build muscle but I am certainly building some muscle and strength.
Protein powder has its place if you want to use it go for it, its not some magical weight loss formula but it is a good way to take on lean protein without much effort.