Ben hafif bir parfüm seçtiğim için kendimi daha rahat hissediyorum.

That’s right: Turkish often omits subject pronouns because the verb ending already shows the person. In hissediyorum, the ending -yorum already tells you the subject is I.

So ben is optional here. It can add a little emphasis, clarity, or contrast. The sentence would still sound natural without it:

Hafif bir parfüm seçtiğim için kendimi daha rahat hissediyorum.

Here, hafif means light, mild, or not strong. With perfume, it describes the scent as subtle rather than heavy or intense.

So it does not mean physically lightweight here. It refers to the strength or feel of the fragrance.

Bir parfüm is an indefinite object: a perfume / a light perfume. In Turkish, indefinite direct objects are often left without the accusative ending.

So:

hafif bir parfüm seçtim = I chose a light perfume

If you used parfümü, it would usually sound more definite or specific, closer to the perfume or that particular perfume.

Seçtiğim comes from the verb seçmek = to choose.

It contains a clause-forming ending plus a possessive ending, and it means something like:

seçtiğim = that I chose / my having chosen

So in this sentence:

hafif bir parfüm seçtiğim = that I chose a light perfume

This is a very common Turkish structure when a whole action needs to connect to another word such as için.

In Turkish, için can follow a noun-like clause and mean because of or since.

So:

hafif bir parfüm seçtiğim için literally works like because of my choosing a light perfume

Natural English: because I chose a light perfume

This is a very common pattern: [verb clause] + için = because ...

Yes. A very natural alternative would be:

Kendimi daha rahat hissediyorum çünkü hafif bir parfüm seçtim.

The difference is mainly structural:

çünkü usually introduces a separate full clause with a normal finite verb
için often follows a noun-like clause such as seçtiğim

Both are correct. The version with için is slightly more compact and tightly linked.

Kendimi means myself. In Turkish, kendini hissetmek is a very common way to say to feel oneself / to feel in a certain state.

So:

kendimi rahat hissediyorum = I feel comfortable

You may also hear rahat hissediyorum, but kendimi is very common and sounds very natural in this kind of sentence.

Because it is the direct object of hissetmek in this structure.

Breakdown:

kendi = self
kendim = myself
kendimi = myself, as the object

So the sentence literally has the pattern:

I feel myself more comfortable

That is why the accusative-type form kendimi appears.

In Turkish, daha means more. Just like in English, sometimes the comparison is understood from context and you do not need to say than ... explicitly.

So:

daha rahat = more comfortable

The implied meaning is something like more comfortable than before or more comfortable this way.

Hissediyorum is in the present continuous form, built with -iyor.

It means I am feeling or, in natural English here, I feel.

Turkish often uses the present continuous for current states, ongoing situations, or general present feelings. So kendimi daha rahat hissediyorum is a normal way to say I feel more comfortable.

Because the two actions happen at different times.

seçtiğim refers to the earlier action: the choice has already been made.
hissediyorum refers to the current result: the speaker feels more comfortable now.

So the sentence links a past cause to a present feeling: because I chose X, I now feel Y.

Not completely. Turkish word order is flexible, but this version is very natural.

The sentence puts the reason first:

Hafif bir parfüm seçtiğim için = because I chose a light perfume

and then the main result:

kendimi daha rahat hissediyorum = I feel more comfortable

You could also say:

Kendimi daha rahat hissediyorum çünkü hafif bir parfüm seçtim.

Both are natural, but the original structure is especially common in written and careful spoken Turkish.