Running Only Way To Stay Happy...WTF?!?

I have recently learned that unless I run for 30 minutes everyday, I will eventually crash and not be happy the day I do not do cardio. This has just only been the case I assume the past couple of years. The last couple of years I became extremely depressed and lost a sense of who I was. I totally forgot my personality and did not know who I was. Before I was confident and exercised but did not demand it for my mental health. I'm just starting to gain my confidence back but I just don't know why I must run at least 30 minutes while others are perfectly fine not even leaving their couch.