Hi, I'm sorry for the late reply.
You shouldn't be too nervous about altitude sickness.
You can buy some oxygen bottles before going to the mountain. They also sell it when you get to the top.
If you want to see snow, I would suggest you to take the long cable car ride. It goes all the way to 4500m above sea level. Yes, there is a possibility to get a little bit of headache or dizziness, but don't worry!