Yep it happens to us all...I got Gracie at 9 weeks and she did sooo good...I think I took her out every 2 hours at first..the first week she went in the house 2 times and I thought boy this is easy!! Then the next week she went in the house twice in ONE DAY and I was freaking out..lol..thinking I messed up somehow...but you start over..stay as patient as possible...NEVER correct if you dont catch them in the act...they won't have a clue what you are talking about if its done already..

She is 7 months now and hasn't had an accident in the house since she was 4 months..but she had probably 6 or 7 up til then...and every time it was MY fault, not hers..she always has to go when she eats...and if she they are sniffing around, take them out or if they are playing hard...they have to go go go..
At about 6 months they can finally hold it for a pretty long time..but still I wouldn't go more than 4 or 5 hours if you can help it when they are under 9 months..by one year they should be able to hold it up to 8 hours or so...
Hang in there~