I have a contract of one year it will finish in August, I already have one year with my actual landlord, I always paid on time but we are buying a new home and I want to break the contract, the contract said that I have 60 days. Do I have to paid all the lease until August or I just loose my deposit.

Talk to your landlord about it ahead of time, don't keep it a secret. I broke a couple lease agreements and never paid any kind of fees/penalties because I told the LL about it in plenty of time and he was cool with it... but if your LL isn't happy with it and there is still a current lease then you are most likely responsible for it, up to 3 months.

If there is no current lease than 30 days notice should be fine...