Astra J 1.7CDTi exclusiv 2010

So I have been letting my issue develop and I still don't hav a clue what the causes are.

No:1, chirping/squeal from engine, does it on idle and now does it when Reving the engine, I'm pretty sure it's not the aux belt because this sounds more at the back of the engine. Once cured by replacing fuel filter but hasn't worked this time.

No:2, engine breathing really hard for no reason what's so ever, has anyone had this problem before? Other minor things that co