I'm not only fat...

I've gone from 150 to 315. Other than basic weight gain issues, it's come with so many other issues. I have plantar fasciitis because of the additional weight on my feet. Getting out of the bed and walking feels crippling. I can feel my chest hanging off my sternum. Chest pressure. I have yeast infections in my arm pits and athletes foot. I have skin tags that have developed. I have pimples and red spots that have popped up all over my chest and arm pit area. My feet are swollen and heels are cracking. I can't breathe. And I'm only 21. I used to be a huge fitness buff. I had a clear complexion, soft skin, healthy hair and nails, bounced out of bed every morning and went for a run. Now, it's like I've gotten SO big that it's harder to get that motivation. It's harder to move my body. Has anyone been through a similar situation and bounced back? Did it solve additional health issues? How did you start?