You are asking multiple questions and you would do well in the future to define what you mean when you ask them.
Is atheism just another form of dogma?
The answer is easily and clearly "no." It is no because you could have spent your entire life from birth to death as an atheist and never thought even once about the validity of the position or any logical component to atheism. Atheism is an absence of a belief. It is not an intellectual stance. Agnosticism is the absence of knowledge, which is closer to reasoning.
This does not mean that becoming an atheist wasn't thought about, it just isn't a requirement. Dogma requires reasoning.
I was raised Catholic, and part of my motivation for leaving Catholicism was my dislike of any kind of enforced structure. However, to my surprise, it seems like Atheism is also dogmatic.
Either these sentences are irrelevant, or they need material expansion to explain how they relate to the questions. Your personal discomfort or your direct experience are irrelevant to the question at hand.
Is this intentional?
Is what intentional and by whom? Atheists are a heterogeneous disaggregated group. Although there are small groupings of atheists here and there, they primarily exist due to discrimination by the larger group. Buddhists are a group; Catholics are a group. Atheists are not a group in the same sense that aunicornists are not a group.
Indeed, atheist is defined relative to another group, theists. It is non-membership, but it is not mere non-membership as "heretics" are also not members, but heretics are still theists.
Is atheism supposed to be only anti-religious or is it more against dogma itself?
Atheism isn't anti-religious but religious perceive it as such because religions are groups and members leaving a group endangers the survival of the group. Theists view atheists as anti-religious. Some are. Some are not. Most do not care about religion at all. If you like joining the group in its tribal headgear, chants, ritual and maybe even dance, go for it. Just don't expect everyone who is an atheist to think you are fully sane.
Atheism isn't for or against dogma because atheism is a description. A dogma is a belief arrived at through reason alone. People make dogmatic thoughts quite a bit and nobody cares. For example, it is dogma that people do not invest money with the intention of losing it since they could simply consume their resources instead. That fits the definition of dogma. It doesn't require any evidence at all. It might be nice if evidence were collected, but it isn't required except for confirmation. Science would require confirming evidence, but dogma does not.
The Pythagorean theorem would fit the definition of dogma, for that matter.
For your next question, you should consider looking carefully at your definitions, how your personal experience is driving this question, and what you really want to know. You should probably post it in a social sciences wiki instead, though.
Atheism is an extremely conservative position, intellectually, in that it requires the fewest assumptions about the world. The claim of a god or goddess, kami, spirits or leprechauns is a perilous assertion of logic unless grounded in an axiomatic system which presumes their existence or there is commonly accepted data to support it. As an example, there is no dispute that Pluto exists. There are disputes as to its classification. The existence of Pluto is not in doubt and so it requires no assumption, other than that nature is real, to assert the existence of Pluto. It may be perilous to assert that it is a planet.
As a disclosure note, I believe that Pluto is a planet because the alternative is that Mrs. Smith, my third-grade teacher, was wrong and that is too devastating a possibility for me to consider. The IAU was wrong and I stand on the authority given by the State of West Virginia to my school teacher. To assert that I may have been misled, that Mrs. Smith may have been misled, or the West Virginia Education Department may have been misled is beyond contemplation.
Take the answers posted here and contemplate both your motivation, your experience and what you really want to know. I think you probably need to ask another set of questions, but I think the questions will probably belong to another type of forum as my guess is that there is little that philosophy can provide. The primary and most profound thing that philosophy provides most people is clarity of thought. Once the thoughts are clear, those thoughts usually belong in the domain of a science or one of the humanities.