I have found from personal experience when I would try to change everything at once and attempt to do it perfectly, the first time I mess up or don't get the results I want, I become discouraged and give up. That's why I feel it's important to let people know it's okay not to change everything at once. I'm still making changes and I've been doing this for three years. Also, having that long-term goal is great, but in the process you want to have short-term goals to focus on. This is another reason why people become discouraged, they focus on the end results and when they don't reach their goal as fast as they think they should they give up.
So, if you have a final goal in mind, set some weekly and monthly goals that will help you get there. Make small changes and improvements so you don't feel so overwhelmed. But more importantly if you're not seeing the results you want, don't give up, re-evaluate your plan and adjust where needed. Now, I know all of this is easier said than done, but having a great support system will make it better. Obviously the best support system is having your friends, family, and co-workers working out and eating healthy just like you are; but, I know this is not reality. So, the best way to make sure you have the best support system around you, is be honest with yourself and the people in your daily lives. What I mean is you have to be honest with yourself in what you need and what you want, then you have to make sure the people in your life understand this is important to you.
Some things I did was I made a commitment to myself that I would not miss or reschedule a workout just because someone wants to go have dinner or lunch. My session is 45 minutes, I can catch up with them afterwards, or they can wait until I'm done. In the three years I've been with FT, I've only missed sessions when I was sick and my doctor or trainer told me to stay home. Another thing I did was I stopped participating in food days at my job. We were always having them and so to avoid the temptations, I just didn't participate. Yeah, some co-workers made comments, but I didn't care. First of all, the majority of the food brought isn't healthy, and then also I wasn't strong enough to say no to the things I shouldn't eat. Now I have my eating habits under control, so I'll participate in a food day from time to time, but not every time.
Everyone has their own challenges when making changes with their health and fitness, and I really believe making small changes along the way will get you the long-term results you want. The other important thing, is to remember, ALWAYS do what's best for YOU!!!! Because your health and fitness journey is about making YOU a stronger and healthier person!