Tumblr theme issues! PLEASE HELP I WILL LOVE YOU 4 EVER? (?

[Miss LOL]

I Have this problem with links on my theme. Whenever i add a custom link it always go to this url with my link then the link i wanted to go. Let me make this clear, I want to add a link to ModernVision So add it, but when i click it goes to my link which is relachee to relachee.tumblr.com/modernvision.tumblr.... It makes it 2 urls. So i made a redirect link so it could go there but when i click it gives me this error or redirect loop. Please im so desperate for help lol. Help me and ill follow you foreverrr. You can see it ur self when u go on my tumblr > the x on the left side corner> networks> click on the modernvision.
Relachee.tumblr.com

[xoxo-gossip-girl]

okay go to customize>add a page>redirect and under your url it says redirect to: and that's where you write the actual site you want it to change to (modernvision).

above that, select "show a link to this page" and where it says yoururl.tumblr.com/url instead of url write what you want the page to be called before it gets redirected