Perspective of the perspective

 as a beginning philosopher, I suggest that you just stop trying to formulate arguments altogether and just soak in knowledge. You are putting the cart ahead of the horse here.

You should be reading a lot and writing down necessary truths so that you can use them as a foundation for your own philosophy.

This proof above is rooted in a faulty premises. Premise #1 isn’t necessarily true, because if man were not, existence would still be because man is not eternal and something cannot come from nothing.

Also, #2 is True, #3 may have been true at one time, but cannot be true now that man exists. And #4 is false, if existence is not, man cannot be because man exists. It doesn’t matter if he is being deceived or not, for if he is, he is being deceived by an entity that exists and not a non-existent entity.

The argument based on context is incoherent. I am not sure what exactly your are trying to achieve here? Also, I’m not sure why you are using the word “context” here? Do you means Being? Why don’t you use the word “Being” (Absolute Being) with a capital B instead of the word “context” here?

Our knowledge is based in context yes, but that context lies within and is formulated by our present knowledge of our own past.

in terms of the existence of an “external other,” it must be the case because your thoughts are internal, and some of your thoughts are not your own. It follows that the external other is a subject, and a subject which is capable of creating many points of view within itself.

I would just drop the idea of the pentagon because it doesn’t do anything for your argument. You still have to prove that infinite regresses are true in actuality rather than just as concepts in the mind. Just because you can conceive of an infinite regresses doesn’t mean that they exist in the world.