You might want to check in with a podiatrist, a foot doctor, or with an orthopedist if you already have one.  Heel pain is pretty common, and there is more than one cause. It can be a bone spur, or (if its at the front of your heel into the flat part of your foot) plantar fasciitis, which can be a bear.  There are certain stretches that will help this. Plantar fasciitis is inflammation of the plantar (bottom) fascia (band of muscle) of your foot. (Try googling it.)  It can be very painful, and take a while to get over, but it can be done in most cases.  Try the podiatrist first on this one, I'd recommend.  The exercises stretch the fascia, usually before you get out of bed, and a couple times during the day.  I'm not a medical professional so you should get directions elsewhere.

     Leg cramps probably are something else, although if you are not wearing good supportive shoes, it all might be related to that.  I have come to depend on custom orthotics that the podiatrist has specially made.  Some insurance covers this, some doesn't.  You can try over-the-counter inserts first, say 3/4 arch supports, or gel pads, but it's hard to know what's going to work.  You may or may not have tendon problems, or you may just need exercise and conditioning to strengthen your muscles & tendons.  I had foot problems in one foot that was solved the instant I got a custom orthotic.  The other foot problems went on and one, chronic tendonitis, arch problems.  I first used an OTC ankle brace, then a custom ankle-foot orthotic, each for several years, and eventually (after 8 years) I had a tendon transfer (sometimes called reconstruction) because one was really weak that affects the arch.  It took a while to build up strength and stamina again, but now I'm doing really well.