I commend you for wanting to make the change. Small changes can go a long way in making a modest improvement in how I feel and making sure I don't gain MORE weight.
Getting rid of processed sugars - for me soda - and I can drop 3-5 punds in a couple weeks off of that alone. Simaltaneously cutting out caffeine (again the soda) and I FEEL so much better - energy levels are more even and I crave water when I am thirsty after a while, not sweets.
I recently started modifying my lifestyle in a more permanent way. I started counting calories - always avoided it and resented needing to write down my meals, etc. But it has helped so much. I use myfitnesspal.com. It is almost fun to do. I aim to do 1200 calories a day to lose weight, but I can eat more.to merely maintain... and not gain. I try not to restrict what I eat, and instead limit portions. So if I want ice cream, we go for ice cream, but I get a kids cup and love it and not feel bad.
Finally, a LITTLE exercise helps. With my goal to lose like 40-50 pounds, I ideally would like to work out at a high heart rate for 45-60 minutes every day. However, it is not always possible, nor am I always motivated to do it. So I promise myself, I will at least tgry to walk on the damn treadmill or climb some stairs for 30 minutes even at a low pace. First, it burns calories, even if a small amount. S., I usually "get into it" and keep exercising a bit more than I intended. Third, it makes me feel better, and I am less likely to give into bad cravings and despair.
I also set reasonable goals. Instead of focusing on needing to lose 50 pounds which sounds huge and might take a year, I focus on losing 15 pounds because I know this will get me down one dress size. I can estimate that will take 2-3 months at a lackluster pace and I focus on that - "in June I will have dropped a dress size!!" Rather than having an unreasonable goal, little milestones can feel pretty good.
So, I have lost about 10 punds recently, but I am doing really well. I have never had this whole life change before. In past, I restrict food and don't exercise, or I exercise and come home and eat a half a pizza. This time I am doing both, and I am not punishing myself by being too restrictive, and I just try to be active. I have considerabel confidence doing it this way and I am making good consistent progress. If I have a bad day, I say, that's okay and go right back to the plan the next day, rather than feeling like all is lost. I heard in one diet book, this is called a u-turn.
Good luck to you. My goal is to have lost 17 pounds by May 6.