I used to get palpitations from the caffeine in the many mugs of coffee I drank each day - when I realised how unwell it was making me I switched to decaff. In my mid-60s I was diagnosed with type 2 diabetes for which I'm on oral medication. My advice to you - if you're prepared to accept it - is to give up coffee completely, while you can't afford it, and stay away from sugary cold drinks if you want to avoid diabetes. It's not easy to go cold-turkey but......