Hierarchical your SharePoint Site Collection and the My-Sites Site Collection is at the same Level. It's not easy to get cross-site-collection information in a Webpart.
https://DemoSP.sharepoint.com/SitePages/Homepage.aspx (normal SP 2013)
https://DemoSP-my.sharepoint.com/default.aspx (MySite Site Collection)
You may need to hard-code the my-Site Url and try to get information from the Task-list.
You can use something like this to get your My-Site Web-Objekt
using (SPSite spSite = new SPSite("https://DemoSP-my.sharepoint.com/"))
{
using (SPWeb spWeb = spSite.RootWeb)
{
//find your list, get infos...
}
}
Hope its a little help.