I noticed the Scorpio thing, too. Scorpio includes sexual organs, reproductive health, and hidden things. Plus, you have the SR MC at natal Chiron. I'm wondering if these health issues are something you've had underlying all along. Maybe not manifesting so strongly, but present in smaller ways.
Getting engaged is a big change. Have there been other big changes in your life recently? Or did your engagement perhaps trigger strong emotions for you, deep down? That might happen if you have any negative associations with marriage, or if you are not entirely sure about your relationship with your fiance. I'm not saying that's necessarily true for you. It may not be at all. But if it is, the engagement could be a triggering event that brings out the underlying issues. Or, some other triggering event could, even if the engagement really is a completely happy event for you.
Emotions don't cause health problems all by themselves, but if there is a physical health problem, major emotional events can trigger a flare up, or be the timing when it gets bigger. That's what I'm getting at here.
If you just turned 26, you're in a third house progression year. That makes Venus (ruler of Libra, your third sign) the time lord--that is, the planet that has extra say for you this year. SR Venus in Scorpio, SR first house: seems to suggest femininity, feminine issues, and the dark or hidden side of feminine. Also, marriage, partnership (no accident you got engaged on your birthday!), and, perhaps, feelings around it that may be deep and secret. Jupiter is also highly relevant, because you have it in the third sign. Jupiter makes everything bigger. You have a lot of swelling--very Jupiter.