Selam aleykum
MashaAllah for wearing hijab this long. Of course there comes a time in everybody's life where people start questioning those things thta we normally took for granted. And at those times sister, shaytan is quick to whisper things among the lines of:
"if you fit in, things will be better for you, so take it off so you don't stand out."
If you listen to shaytan and follow his advice, the next thing he will say is: "when a boy approaches and you take your distance, then they will not understand it and be upset with you since they have a different culture, so you should be friendly to them."
If you listen to that to, then next thing he will tell you is:
"Well, you don't have to drink alcohol when you go out with your non-muslim friends, and you might even have an opportunity for dawah, so go with them to that bar, it's not like something bad is going to happen"
And he goes on and on like that, and before you'll know it, the difference between you and teh disbelievers will become smaller and smaller. And the more you adapt their behavior the more difficult it will become to follow your religion. and the more difficult your religion becomes the less you will believe. and then you're stuck in a vicious circle.
Now, you might be thinking "it won't get this far, I'll be able to keep it under control" And who knows, maybe you will, maybe you wont. But remember that Allah subhana wa ta'ala guides whomever he wants and lets astray whomever he wants. What would Allah subhana wa ta'ala do with those who deliberately chose not to follow his rules? Only Allah subhana wa ta'ala himself knows, and we do not. But frankly, if I were you, I wouldn't want to take the risk of loosing his guidance, you may plan to only take off the hijab for two years, but if Allah subhana wa ta'ala stops guiding you, by the time two years are gone shaytan could have conquered much of your heart. And you might not have the will to put the hijab back on. Again, Only Allah subhana wa ta'ala knows, and I know not, but why take the risk?
My advice to you sister, keep shaytan at a distance inshaAllah by striving in following the rules of Islam as much as you can.
May Allah subhana wa ta'ala guide us on the straight path.