As with many here, I was/am an iPhone user. I kept my iPhone 4 until recently because I wanted a bigger screen for so long. The iPhone 5 was a huge disappointment for me (and many others who are looking for a wider screen. And no android device came close to the smoothness of the iOS, until now. I'm a "techie" person if you will so I have done all my homework prior to purchasing the Nexus 4. Despite it's many flaws, I still went with the N4 because it is a Nexus device. I had seen my friend's SG3 and many other lower end Android phones and just not happy with them. I need an actual LCD and not some lame ass pentile ed screen. I need a "retina" screen as well since I'm really spoiled by the iP4. I need regular updates quickly and won't leave me hanging after a year.
To be really honest, it took me about a week to get used to all the settings that I was accustomed to on the iP4 (jailbroken with many awesome tweaks). Eventually, I was able to find what I was looking for and a lot more. For example, there are widgets for virtually everything! Every screen can be customized with widgets up the ying yang. Best of all, there are a lot to choose from. Some are , most are OK, and if you do some research, you will be able to find one perfect for your needs.
As for OP, everyone time you get a new "toy," whatever it may be, there will be a learning curve. I've seen people used an Android phone before so I knew how to answer the phone prior to getting my own. You just gotten used to using the iPhone, as I have, for 3+ years! But I'm mostly adjust. I'm still having a hard time on some things such as the calling app. Still takes me a while to edit a contact or find what I'm looking for. In the default SMS app, you can't insert a contact to send a message to. That's just stupid. But I guess there's an app for that...
The best way to adjust to the best Android phone right now, find a friend who's been using one for awhile and throw whatever questions you may have at him/her. Even though the hardware may be fragmented, the software aspect is pretty much the same. I have already fallen in love with my Nexus 4. If you give it a chance, you will too.