automatic way of posting in facebook and to repost in spareroom

I have a list of groups I want to post the same in facebook. Some description and pictures. Also something to "repost" on spareroom (like freethetree with gumtree). I ACCEPT ANY IDEA OF HOW TO MAKE IT. However, I will try to describe it more, with mines: I need a way (maybe a chrome add on, or a script on Imacros in case, or whatever that solve the thing) to post on facebook. It is a very repetitive job, to start a discussion at facebook, pasting my post, and then adding the pictures... and then pressing post, and to another group. I need this to be able to make 1 post every 1-3 minutes (randomly, so facebook does not realise this is a bot). Maybe It can be done with a way of creating the post on one group, and the sharing it in the rest of the groups. I need the post to spread around all the groups at least 2-3 times per day. That would be for 100 groups: 100post morming, 100 post evening, 100 post night. It is very important that there are preventions for facebook not to realize this is a bot. The would not like it, and I might get ban/temporary block.