Lied to my family - how do I correct this?

Kill yourself

I am in my early 20s and I started university in 2013, but I ended up hating the course I picked to study although I decided to stick at it knowing that I'd want to change course anyway. As my dad helps me fund university, he was totally against the idea of me changing courses at the university I was attending (as there was always the risk I'd end up hating the new course too) so he told me either to stick at the course or to move back home and attend my local ex-poly university and pick a course there - I wasn't happy with this as it felt like I'd be taking a massive step back especially after being independent and loving university life away from home for a year.

I ended up lying to my parents and told them I'd stick with my current course but I have actually changed courses and have just finished first year. I love my course and am much happier than I was last year. But my parents, and all the rest of my family, think I am moving in to my 3rd year now but really I am going in to 2nd year. Luckily my current degree is similar to the previous, so I could tell them I switched in second year. I was thinking of telling them I had to repeat this year, but I can't really do that as they know I have been getting good grades. Also, as it's a humanities degree I can't really say I have a placement either. I could say I have decided to do 3rd year on a part time basis, although they'd probably be against this as it would be more costly etc.

I know the truth will eventually have to come out but I am not really prepared to tell them until my final year/ once I graduate, and even then I wouldn't tell them the full truth, just that I transferred mid way through or something. Does anyone have any suggestions?