I have already experienced lunacy through faulty yoga practises 10 years ago. (manic, extremely joyful state, voices, visions etc). Now I feel these cold heart shivers and no joy at all like I’m in a black pit with foggy brain.

How can I rectify it if is caused by kundalini?
its like all the finer feelings have left me for good
I learnt all yoga from a book, never done it in a group with a teacher. I practised Uddiyana bandha and mula bandha and headstands and pranayama while being in a passionate, impatient state and smoking. I was meditating once and lost myself totally and became one with the birds I was hearing. I also had a dream where I was taunting this girl I was obsessed with at work and she turned round and had eyes like medusa, full of fire. When I woke i looked under the sheets and sparks were coming out of my solar plexus area, lighting up the darkness- Is this something to do with kundalini affecting that chakra?
I have not done any yoga for a number of years due to these effects.
Here is a warning for people taking up this practise
http://kundalini.se/eng/hatha-yoga.html
http://kundalini.se/eng/stories.html