Wrong! Sorry you got it wrong.
First of, your detection is not right.
You can feel chakra enter you as its not a surge. Infact you won't know you are put in a genjutsu until you are actually in it.
Also you can't just say, because you see snakes, you are in a genjutsu. As a matter of fact, the snakes might be a sort of summing jutsu or natural snakes from the terrain.
What you should have done to notice you are in a genjutsu is see whats wrong with the sudden appearance of snake.
"say, you did not see me make a blood sacrifice, nor did you see me make handseal and slam my hands. So this rules out the fact that is not a summoning jutsu. Anothe fact is that, the snake was not there before and if it were to be natural snakes, they must have been underground below you but you did not see any hole from which they surface. Puting all this fact together, you can now conclude, its some sort of genjutsu. Now if you are a chakra sensor or a doujutsu user, you can confirm by checking your chakra network if your chakra is disturbed.
Secondly, I was thinking you'd try to use pain to break away from the genjutsu since, I've not taught you how to spike chakra yet but your try is incorrect.
Puts you in another genjutsu where you see butterflies flying everywhere blocking your vision.
Detect you are in a genjutsu but don't break from it yet.