All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Treating your father with kindness and working with him to provide the whole family with livelihood constitute one of Allah's blessings on you.
So, your brothers' laziness and their weakness should not make you leave the company or ruining it. This, in turn, does not justify mistreating your father.
Thus, you can arrange with your father for an amount of money in return for your work with him. But, if he refuses such a suggestion - although we think he will agree - it is your duty to obey him and treat him kindly in all cases, since this is his right on you.
In addition, you have to advise your brothers to work and avoid being lazy and dependent on others. May Allah guide them and grant success to all of us in this worldly life and in the Hereafter.
Allah Knows best.