Is my leaving my job with my father to pursue marriage without his help considered a sin?

If you are in need of marriage but do not possess the means, and your father does not give you a proper salary nor assists you with marriage expenses, then there is no blame upon you for leaving work with him to earn a livelihood and get married, especially if your father is capable of working without you, while striving to be dutiful to him and please him as much as possible.