Anyone ever had collagen or fat injections?

[Mysteryagain2]

Hi there!
I have a very slender face that seems to become more and more slender as I age, and it makes me look thinner than I am... which is not good! people assume I am getting skinny, when my body weight is the same as always! it is just my face that is thinning! But the point is... not just because people make comments on how thin I look but also because I personally don't like to have my face becoming thinner that I am considering getting self-fat injections or collagen injections in inner corner of my eyes.
I don't have undereye circles, but the lack of fat in that area creates a line from the inner corner of my eyes to my cheeks that creates a shadow and hence creates the optical illusion of a) having undereye circles b) being skinnier than I am, c) the "sunken" look there makes my nose appear more protruding or large or long or I don't know what, but the point is... this "sunken undereyes" just makes me look bad in many ways.

Someone long ago told me about the possibility of having some fat injected in the area, to level it up and erase that "bad effect" of a "sunken undereye area". But to be honest, I don't know if this person ever had that procedure done, if she knows someone who does it and, above all, if it is safe and really works.

Has any of you have had that procedure done?
If so, does it leave you looking bruised for many days in the area where the injection took place?
What was injected? your own fat or collagen? I was told it is not the same.
And how long did the results last? (I know the fat or collagen is usually reabsorbed by the skin, that it is not a permanent fix for my problem).
Anyone had fat injected somewhere else in their face, say, "outher" cheeks? as to look with a rounder face?

Sorry I ask so much but I do want to hear testimonials of real people. The docs who do that kind of stuff tend to always talk of the good, and not tell you the bad side of these procedures, or whether or not they really make a difference.

Any info will be appreciated!