WordPress menu>Custom Link: removing my link formatting and adding %20

That is perfectly fine behaviour of WordPress. You can´t just paste markup in the href field, the input gets sanitized.

Use the built-in functionality to provide special links with classes if you want a different styling. See the attached image for those fields.

You will have to activate those options through the options tab at the top of the page, though.

Edit menu entry

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)