First of all, if you have the means to get therapy then do so. If I could magically wish for one law to be decreed and obeyed universally is that therapy should be mandatory for everyone. I said everyone. People have no idea how much the world would be better after a few months. It really helps in wonderful ways, so there is absolutely no shame in that. No matter what if any condition a person has. And while therapy/counseling is not a silver bullet to solve any of modern days hardships (such as anxiety, depression, or PTSD), it does make these conditions a lot more manageable.
Regarding your colleague, I imagine it is hard to you to differentiate between intentional bullying (from malicious people) and well-meaning jokes (from well-intentioned people).
One of the hallmarks of well-intentioned bullying is how the person reacts when you ask him/her to stop some specific behavior. If a tell you a joke that you find offensive and you complain to me, even in a discrete (but not cryptographic) manner, be sure I'm not telling you a similar joke, ever again. No need to ask twice.
Malicious people, however, the ones who might want to annoy you have a good chance of either repeating the same offense or influencing others to engage in the same provocation. If you want to test it, maybe pick some small non-PTSD inducing pet-peeve of your that you can manage well and ask the suspect offender about like it is a relatively big thing for you. See how often it starts happening then. If you report to a manager that bullying behavior is re-incident after a one-to-one (but cool-minded) request for ceasing, then you have good evidence that management needs to take action and that the person is deliberately crossing lines or testing limits.
All that being said, do consider that everyone has problems of their own. Hence my aforementioned law proposal. So colleagues of yours also engage in fights and arguments, some people may dislike each other and the vast majority of it has nothing to do with you. If you've snapped at a guy at the workplace, you are not the first nor the last. And things need to get a lot more serious than what you describe before one should consider quitting or firing someone. So, people need to have some degree of tolerance towards you, the same as you should have towards them.
"I spoke with my supervisor about this since he has hints about my situation"
Your supervisor should not have "hints" about your situation. He should have a very informed view of your PTSD. He does not need to know the specifics of the trauma, but he should know the exact medical terms (Post-traumatic stress disorder for serving in the army/due to family issues/related to a past violent accident). It is his job to inform himself on how to best manage a person with your condition, but it is also your job to make sure he is aware of what he is dealing with.
Keep in mind that mental conditions are medical conditions. They are serious and should be treated as such. But if you didn't have a mental condition, you would not be owned whatever special treatment or caution your condition may require.
To give a cruel example, if I'm scheduling an event and there is a person with celiac disease I would make sure that there will be gluten-free food for him/her. If however there is a person with a "made-up allergy" (meaning an excuse for an ill-informed diet), I'm simply not bothering myself about it. While this is not a recommendation on how anyone should handle this situation and I'm not being a role model here, this is how you should expect people to act: They respect what is real and known, they disregard bullshit.
If your boss has only "hints" of your problem, then he is not equipped to tell apart what is real and what (if anything) is bullshit.
Finally, if you snapped at your colleague and you believe he didn't deserve this, make sure he and your manager know that you think so and that you are sorry about it. Maybe write an e-mail, maybe ask your supervisor to apologize on your behalf. Clarify if needed that you acknowledging your behavior as unacceptable is not excusing his behavior, or any action of him that induces pain into you.
