Do how ever you feel of course but I would say deffo program your own patterns.
As you say it seems to take you forever but this is all part of it.
Take your time and remind yourself there is no rush.

Its down to whether you want a track that took you some time to make where all the sounds and patterns are yours or crafted by you.......
Or do you want a track made with premade loops that you knocked up in a few hours.

Enjoy yourself and take your time, then still be unhappy with the results possibly:)