Now or later?

I’ve been planning on leaving my job and switching to my own business for over a year. The date is fast approaching and i’m not as far as I would like to be as in business not finished but idea firmly in place.. I’m considering extending my date and staying in my job til end of December, but I feel conflicted. On one hand I feel like if I stick to the original date i’ll have the added pressure to get things done and keep the commitment I made to myself, on the other hand if I extend to December i’ll have more savings and time to prepare and security… any advice is appreciated i’m having a hard time with this one.. I need to make a decision soon because my lease is up end of June and i need to decide whether to extend it if not.