Vauxhall Astra Turbocharger Problems

Hi, my problem started a few weeks ago, every time i change gear, i get a cloud of smoke behind me also sounds really loud, when going up hills it loses all power down to about 5mph, does anyone know what could be wrong please. Thank you...

6 yrs I was sold a 2007 1.7 Astra with 50,000 on the clock. Before 2,000 miles had gone the turbo went. It was replaced at huge cost and now, 35,000 miles later the replacement has also failed . I kept getting an intermittent orange car...