You will not be able to master anything till you tame your mind first! You must first take baby steps towards your goal and move forward each day. Fitness is not waltz where you take two steps forward then two steps backward! If you do that with your body weight you will have exhausted yourself with constantly shedding fat then putting it back on again. Eventually your Mind as well as the Body will totally give up, which is not a good thing.
Fitness is all about staying healthy. The extra weight that you may have recently put on will automatically disappear if you are alert to your girth increasing in size! I cannot promise you that you will never fall sick in your entire life but I can confirm and the fact is that if you stay fit as well as healthy even if you fall sick or get injured, your body together with the immune system will be in such optimum condition that you will bounce back just as quick. It is all in the mind.
Most often you would have noticed that folks who are overweight and also neglecting of their health tend to think that everything is fine. However, it does not happen that way at all. In fact, that is just ignorance and what is called as burying your head in the sand. Ignorance cannot be bliss. One needs to understand this. But all it takes is one minute medical condition, injury, or sickness for them to hit a downward spiral because the body is too weak to defend itself and recoup. You must allow your body to grow strong and build its immune system and develop your mind.
Why should you take that chance and just survive at the mercy of medicine and doctors and hospitals when you can become strong, fit, healthy and happy always!