How do I thicken my arms? make me very complex?

Well, as you can see in the photo... I have very skinny arms.
I went swimming for a year and never developed muscle mass

my arms always shake and I can't carry very heavy things because I start to shake (the maximum weight I lift is 2 kilos)

They make fun of me for my very thin and weak arms, I went to the nutritionist and I started to gain weight, now I have a bigger stomach and
How do I thicken my arms? make me very complex?
How do I thicken my arms? make me very complex?
How do I thicken my arms? make me very complex?
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+1 y
my legs are thicker but the arms are almost the same and the change is minimal.

what do i do to thicken them?
eat a lot of flour but it didn't work either

How do I thicken my arms? make me very complex?
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