In a recent translation request.

"Senden çok seviyorum senin özlemeni"
=I love missing you more than I love you.

Ablative has been hard for me but seems that it is more like "subtraction" in arithmetic.

Loving you is less than missing you?

Is this right?

I agree with si. Can I just add a little way of thinking about it which helped an English speaker when learning it to find it logical?

(A)
Think of the other use of -den/-dan: from.

When you start out measuring FROM THE POINT OF of the first word, the second word is more, or less, in terms of the item you are measuring.

e.g. In the example we were measuring how much something is loved. When we start measuring the amount of love FROM THE POINT OF how much I love you, we find that the measure for how much I love missing you is more.

Ayşe benden daha uzun boylu
Ayşe is taller than me. When we hold the tape measure from the top of my head we find Ayşe is taller.

Ayşe benden daha kısa boylu
Ayşe is shorter than me. When we hold the tape measure from the top of my head we find Ayşe is smaller.

e.g. Bu kitap o kitaptan daha güzel.
This book is nicer than that book.

O kitap:that book
O kitaptan: "starting from" that book : than that book
Bu kitap: this book
güzel: nice
daha güzel: nicer

(B)
You asked whether -den/dan means less not more.

We can use -dan for "more than" or "less than" sentences. The thing that makes the difference is whethere we use daha (more) or az (less) with the adjective.

e.g. Bu vazo diğerinkinden daha az pahalı
This vase is less expensive that the other one.

Bu vazo: this vase
diğer: the other
diğerinki: the other one
diğerinkinden: "from" the other one: than the other one
az: less
pahalı: expensive

e.g. Mehmet Ayşe'den daha az çalışır
Mehmet works less than Ayşe

(C)
Here is an example of how this construct can be useful in real life:

Bu mektuplar ilk mektuptan daha hafif.
These letters are lighter than the first letter.

(This was the first time I used it for real: the day after learning it. I was sending 5 letters to England, and one was heavier than the others. The guy at the post office weighed the heavier one and was going to charge me its cost for all 5 letters. I was so proud of myself I could put him right. Before learning this grammar I would have just overpaid for the postage and felt sorry for myself.)

(D)
Another use of it is "a little more than" and "a little less than"

e.g. Beşbinden fazla kişi geldi
More than 5000 people came
Beşbin: 5000
beşbinden: "from" 5000 = than 5000
beşbinden fazla: more than 5000

e.g. Bir tatlı kaşıktan az
Less than a dessert spoonful
Tatlı kaşık: dessert spoon
Tatlı kaşıktan: "from" a dessert spoon: than a dessert spoon
Tatlı kaşıktan az: less than a dessert spoon

Thank you all, that was helpful.

görüsmek üzere

thanks MarioninTurkey for your explain
i understood that:
when we use only daha+ adjective.,it means more than
ex.Ayşe benden daha uzun boylu

but when we use daha as+ adjective, it means less than
ex.Mehmet Ayşe'den daha az çalışır
and fazla mean too much
but a little less than , we use az
ex. Bir tatlı kaşıktan az