Good, at least you identified the problem. I am always nervous about resizing partitions, and after you do any such thing, it is essential to run fsck to make sure they are all okay.
It pays to be wary of canned instructions about how to do things in a wiki, errors can creep in to the code and your mimicking of it.
I generally write things down on a piece of paper to make sure I am clear when I do the resizing, and then check what I am doing many times before proceeding, and making sure to have a good backup I can use if it does not work out.
That particular page has several different ways to go about resizing, but I did not follow it precisely. Instead, put together what I knew made sense with what I found there, to get the general idea, and played with my final command list a few times to make sure I understood them. It might be good, if you have not already done so, to carefully study both fdisk and parted, to make sure you understand how they work, before the next time, so you can identify pitfalls in any code you copy from the web.