As you tried lot to fix the problem but some times it happened that you cannot do that so just consult a good garage or a car care shop. i think this is problem with the engine just check it out.
good to hear that you have sorted it out by yourself but if you are unable to do that any kind of issue so just go to the ay car care shop in order to save your time and vehicle.
Thanks for your information one of my friend also looking the spring at cheap cost but he was unable to find so i will refer him to visit this site and can get the cheapest one.
I will suggest that first you search a good reputed car care shop because i am also going for my vehicle to top class garage where they have experienced staff.