Node using wrong version after Brew Install

I'm using a Macbook with the latest macOS (10.12.3), and I installed Homebrew by running:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

After that I installed node:

brew install node

And tried to upgrade it:

> brew upgrade node
> Error: node 7.8.0 already installed

I got an error saying the version 7.8.0 is already installed, that was expected since I had just installed the most recent version.

Problem: on the terminal I ran:

> node --version
> v4.4.5

and got back an old version that apparently was already installed. Also, when I install some new package through npm I get a warning saying the package requires an newer version of node.

Question: I seem to have both versions of node installed on my mac, how can I use the most current one? And how can I uninstall all other older node versions?

Thank you very much for your help!

My problem was solved following @theWanderer4865 suggestions in the comments.

First, I uninstalled the node version I had installed through brew: in the terminal I executed:

> brew cleanup
> brew uninstall node

Second, I removed all other node versions I had installed by running:

> rm -rf /usr/local/{lib/node{,/.npm,_modules},bin,share/man}/{npm*,n‌​ode*,man1/node*}

Third, install node again using nvm:

> nvm install node