Head gasket repair but still got issues

ive got a mazda 5 7seater on an 07 plate and I had my head gasket repaired recently but the car still isn’t right. The head was pressure tested and skimmed , so no warps or cracks found. The timing belt and water pump were replaced . The 1st time I took it on a long journey the car broke down. Something to do with bolts shearing off and ripping through the cam belt and damaging the rockers. All this has now been fixed but the car chugs when idling and almost bounces. When you pull up after driving you can hear bubbling . The header tank is OK as is the oil , however it overheated due to a corroded pipe which is now fixed , but I’ve got up this morning in frosty conditions , started the car to defrost it and there is now a puddle of what looks like rusty water under where the header tank is. Someone please help, im a mum of 3 in my 30s on a teeny income with fibromyalgia and arthritis, I’m still paying off the original 1200 pound bill and can’t afford to buy a new car or be without one as we live in a rural area.