Without repeating what others have said, you are not a disappointment at all!
There are thousands of people on foundation year, and even access to HE courses, it does not mean you have terrible grades either. A lot of people don't fully understand what a foundation year is so try explaining this to them. It's always an amazing time to get to grips with the transition to University and then when you go into your 'first year' you will be ahead of others and be able to hit the ground running!