upgraded now I have issues!

We were having trouble with hacking over a period of time and i was given advice to upgrade my plugins to sort out the issue. I did that, but we had a wide variety of plugs in there that said (up-grade me) about 30. As the web site was set up by some one else.

I also upgraded to 3.5.1 and did not de-activate my plugins in order to do so.

Since finishing the above, I have – fixed the hacking issue, however we have a new issue.

In posts you cannot now add media images directly to the post or as the feature image, you can add images to the media library but you cannot connect the two.

I can also not schedule posts at all, just draft or publish.

And I cant add tags either, it does nothing.

I did do a back up before I started all of this …

And I have tried un-installing some of the plug ins to see if that will fix it but it hasnt?

help ! any ideas?

Tracey