How do you deal with sadness and no motivation?

Since March I have been dealing with sadness and no motivation and food has become my comfort. I bought fb plus thinking it could be a great motivator but the truth is that I don't believe in myself anymore. I don't believe I 'll achieve a body I like or the job I dream. I loved completing fb programs ( I have been working out with fb for 6 yeras) but now when I finally start a workout I keep doing it literally crying. I feel like in a loop where I run and run and am tired but arrive nowhere. Sorry for this sad post and thank you for listening to me.