A friend of mine also has Windows 98 and loves it. I know Microsoft is also ending support for Windows Millenium Edition. I have had no problems with XP since the last major update two years ago. I think the people who have problems (and the ones I work on) do not use virus/spyware protection, have an active firewall, and/or use the security updates.
If I were you, I would limit my risk by using theFirefox browser instead of IE. When it gets closer to Christmas, buy a nice computer with XP. You are probably at the stage where your computer couldn't handle an upgrade to XP.