I have had tendinitis for 15 months tried conservative measures and also had my foot in a cast and cortisone injections in the insertion of my achillies but it is now 6 months later and after doing stretches and wearing insoles in my shoes it seems to be much worse and hurts all the time even when I walk I don't have any tightness but I carnt push off with that foot or walk up stairs without pulling myself up using the hand rail what should I do

I would recommend you go and see a good podiatrist, they can evaluate this problem and offer several solutions. My sister had similar problem, had surgery to lengthen her achilles, and now walks with no pain, no problems . She suffered with this for 2 yrs before finding solution, and went to several doctors who could find nothing wrong.