I was having heal pain daily. Typically from the moment I got out of bed. Going down stairs first thing was particularly painful and I had to do it slowly.
I assumed it was plantar fasciitis and started doing all of the stretching and exercises recommended - no change. If anything, things got worse. It was so frustrating.
Finally I went to see a podiatrist. He did a quick xray. I have a bone spur on my heal - no stretching or exercises to make that bad boy go away. Ended up having surgery - long recovery since the bone spur was behind my achilles, but no pain since. Heel now feels great.
If you're applying fixes that don't match the cause, you won't fix the problem. Yours might be plantar fasciitis. It might be something else. If it's really bothering you and other things you've tried haven't helped, it might be worth talking to a professional.