I only stopped eating meat last year and i thought it would be hard but it was pretty easy once you know what to eat, were lucky we got sabjiya lol. Im sure if you try then you'l be able to do it. Try it for like a week or something and see how it goes
As for the lust problem try looking at girls like your sisters that way you'd have more respect for them rather than letting bad thoughts enter your mind or you could try doing more paat because it can help loads if you focus and do it properly