Hey there friend!
Death by jumping is not a good idea at all in my opinion. Depending on the height of the building, many things can go wrong, leading to you being paralysed, thereby not only not being able to live a proper life, but also not being able to attempt this again. Suicide really is something you can only attempt once, even if you fail in a lot of cases.
What's the height you want to jump from? What is beneath the hotel where you'd land? Why would you risk injuring yourself before the attempt, thereby activating your SI even more, by cutting the glass? What if you are caught beforehand?
These are all things you should consider. As I see it, suicide should not be an impulse decision, as not only might you come to regret it in your final moments if it's impulsive, the chances of failure are comparatively high. Always think.
If you want to talk, vent, whatever, you can reach out to me :).