Dystopian Sci-fi: Virtual Time Travel in the Future that led to a Glitch in the System

[Monalissa]

I read the book around 2016. I can remember there's "21st Century" in the title and I think it has a blue cover (but I'm not quite sure about the book cover). The book was bought from a thrift store so it's really old and tanned, borrowed it from a friend. Okay, spoiler ahead.

The beginning was vague to me now but the remaining plot was basically about "virtual" time traveling in the future since it was mentioned there that physical time travel will never be possible. So they go inside a room or tube, idk, but they're naked. I can't remember if something has to be injected into them or they need to drink something? Either way, they were put to sleep and the virtual time-traveling starts. The major conflict was when the virtual self of the main character started smelling things. That was supposed to be abnormal. And then they started to get physically hurt and that's when the glitch started. That's all I can remember. I can't even remember the ending. I hope someone here had read the same thing.