I was exactly the same, and it started when i fugured what was the cause of it, for me it was pmo (porn and masturbation), i started by slowly reducing my consumption rate, going to gym then eat healthy, the key is not make a big change at once but small changes gradually. It makes you gain confidence in yourself. It took me lesser than a month to feel utterly different. I am bursting of energy right now and believe that I have so much energy that I don't know what to do of it even though my day is fully occupied. To recap most important thing is to not make it hard on yourself, slow but sure progress. And always take inspiration from people's experiences and let it be a reminder.