I was thinking Peter as well. Your father figure is murdered due to your life choices, the love of your life is murdered by your greatest foe all before the age of 25

"Most mentally affected" by what? The onset of super-powers/their origin story? Their super-heroing career?

Sticking with PTSD would be better than substituting the vague "mentally affected", if that's what you meant.

Spider-Man suffered severe personal trauma, through the violent death of Uncle Ben. The revelation that it was at the hands of the crook he let go adds both a survivor's guilt and feelings of direct responsibility, which fuels his desire to stop criminals, lest someone else face a similar trauma. He had to take on adult responsibilities in his teen years, which has shaped him, both positively and negatively. On the positive side, it has boosted his maturity and allowed him to view things through more adult eyes, which has kept him more level-headed. At the same time, he drives himself because of the guilt. I would say, on the whole, he is fairly well balanced, from a mental health standpoint and functions at a high level, with periods of high stress. I would not label him as suffering from PTSD.

Ben Grimm has to live with the loss of his human appearance and goes through the feelings of loss and depression common to those who have lost limbs or the use of them and/or suffered disfiguring injuries. There is probably some PTSD from the crash, in the early days, coupled with feelings of loss and alienation. However, Ben has grown beyond most of that and learned to accept his fate, through his relationship with Alicia, his bond with Franklin, and the familial relationship with the FF, not to mention professional friendships with various superheroes, especially his poker buddies. Ben grew to accept his fate and rise above it, to the point he really is the "ever-lovin' blue-eyed idol of millions." He also functions at a higher level, with periods of strength and melancholy; but not what I would label a clinical depression, nor do I believe he still suffers PTSD. He has dealt with it.

Daredevil carries a lot of emotional trauma scars, from the loss of his mother, at a young age (even though it turned out she was alive) to the murder of his father, his blinding, his dysfunctional relationship with Elektra and the loss of her, various failed relationships, plus physical scarring and mental issues, due to the acts of Kingpin.He definitely has deep-seated issues in regards to romantic relationships that are likely tied to his parents' relationship and feelings of abandonment. It likely causes him to sabotage his relationships before the women can hurt him, if you look at Karen Paige, Heather Grant and Natasha Romanoff, as a group (those are the ones I have the most familiarity with). The life of a superhero is probably driven a bit by survivor's guilt, not to mention professional guilt for representing clients he knows are guilty, though he helps bring them to justice, as Daredevil. Born Again shows the most mental trauma, as Kingpin systematically destroys his life and drives him to the edge; but, the point of the story is that he comes out the other side and rebuilds and is strengthened by it. However, I don't think it helped improve his relationship problems.

Hulk is pretty much reduced to child level, which suggests he isn't necessarily suffering from anxieties or psychological disorders as devoid of the more complex adult mind to comprehend such things, in the old days. banner is one screwed up puppy. Anxiety and depression, likely bipolar, possibly on the autism spectrum...that's him. Add the retcon of childhood abuse, leading to multiple personality disorder and you have probably the most mentally ill superhero of the Marvel Universe. As Banner. Hulk, as a personality, is reduced to basic levels.

Storm suffers from claustrophobia and probable survivor's guilt, plus the physical and emotional trauma of their battles. Whether or not she has an outright personality disorder or has suffered breakdowns or PTSD would be open to clinical study. Definitely mental health issues there.

Rogue has alienation, due to her powers, plus multiple personality disorders, from memories absorbed through physical contact and the transference of abilities. Then, she has sheltered with opportunists who used her abilities, adding more dilemmas and guilt for transgressions she was manipulated into committing, by adults. As such, she has much in common with an abused or exploited child.

Ms Marvel suffers from identity issues, PTSD, substance abuse, survivor's guilt, rape (in a physical and mental sense) She's another messed up puppy.

You didn't include Cyclops, who has anxiety issues, survivor's guilt, PTSD, emotional loss, alienation, codependency issues, physical and mental abuse and a host of other issues. I would rank he and Ms Marvel as the two most damaged heroes in the MU, with Banner in a category by himself.

What of the sociopathic tendencies of The Punisher?

Captain America's loss of Bucky in WWII had a lasting effect, to put it lightly.

Ms Marvel suffers from identity issues, PTSD, substance abuse, survivor's guilt, rape (in a physical and mental sense) She's another messed up puppy.

Not just raped but raped by her "Son".