You're not loopy, very normal by the sound of it. I haven't had the same experiences as you but depression is a common side effect of any cancer treatment. And I mean real clinical depression, as distinct from feeling upset, confused, weary and scared! So take heart, your reactions are extremely normal and bouts of misery can also occur when things are actually looking better. The improvement 'allows' you to have the reaction you have kept back when you knew you were too unwell to cope with it. So let it out. Chances are you will feel better. If it continues of course you should seek medical advice as depression can be treated. Sharing your feelings here is a useful outlet, you will find lots of support. Coping can be hard work. Take care.