Get total of unique array element of an array within an array PHP

I have following array

Array
(
     [0] => Array(
         [0] => Water
         [1] => 0.5555)
     [1] => Array(
         [0] => Jojoba Oil
         [1] => 1)
     [2] => Array(
         [0] => Water
         [1] => 0.3)
     [3] => Array(
         [0] => Coconut Extract
         [1] => 1.2)
     [4] => Array(
         [0] => Walnut Extract
         [1] => 1.1)
     [5] => Array(
         [0] => Water
         [1] => 0.5555)
     [6] => Array(
         [0] => Peptide 1
         [1] => 2)
     [7] => Array(
         [0] => Preservative
         [1] => 0.5555)
)

And I need the following output(by adding the value of repetitive key and display once e.g 'Water')

Array(
[Peptide 1] => 2 
[Water] => 1.411 
[Coconut Extract] => 1.2 
[Walnut Extract] => 1.1 
[Jojoba Oil] => 1 
[Preservative] => 0.5555
)

var dump output:-

and also sort by the sum in desc order Thanx in advance...