Emmasch

Please help, i am a single mum and i have big issues with my car. I have a Vectra 2.2 2007 auto Direct No engine light on no warning sign .... My Vauxhall vectra 2.2 direct automatic Has lost all power It started a few weeks back I noticed slime on my oil dipstick, this terrified me so i asked my xhusband to have a look at this I also noticed slight signs of oil in my Cholent water, her tempature guage since i owned her rarley went above 90, but she for the last couple of weeks seems to sit ar 95 and slightly above, her fan seems to be constentlly on, the temp does go down. I have had a complete oil and coolant drainage, new oil filter also. Garage also put somthing in the enguine called stop leak and no further sign of this problem. However i was driving home 2 days ago and i noticed she suddernlly had no power regardless of how much i pushed on the throttle . I managed to get home and the called the RAC who looked at my car and put the diagnostic computer on, no faults found, so the RAC man took my car for a drive and suggested maybe she needed a gear Box oil change, so thats also since been done but still no change please can someone help .... I cannot afford to keep going to garage and not have a diagnoses. Sorry to ask for help but i dont know what more to do . Maybe relavent i dont know but a month or so ago my car souned rattley under the car. She was put on the ramps and the rattle was coming from the middle and back of exhaust, the brackets holding it was snapped, the garage made some brackets and did some welding ungerneath to hold the brackets in place. Maybe i am worring so much but their still seem to be slight knock/ underneath but spings bearings all checked and seem ok. Any advice would be most greatful, and i very much appresiate you taking time to read my post. Thank you