Hello @andreasschmieg and welcome to Mayo Connect. Well, you may be new to the MGUS club but you’re in good company. We have quite a few members with MGUS and I think you’ll find them very encouraging and supportive. Anytime we get a diagnosis of something we’ve never even heard of before it’s natural to be filled with the mental terror you described.
But knowledge is power and I think once you’re more familiar with with what MGUS is all about and that this is a slowly progressing situation that may not change in years, you’ll be a little more at ease. I know what it’s like to wait for that proverbial other shoe to drop. The thud isn’t always as loud as we imagine. ☺️

I’m posting quite a few links below. The first is from a discussion, I Have MGUS. One reply that I think will be most helpful, to get you started, is from our member @pmm who has MGUS. She’s so gracious and willing to share her experiences with others and I think you’ll find her very reassuring. Here’s her comment I’d like you to read:
https://connect.mayoclinic.org/comment/842935/

It’s from this discussion group:
I Have MGUS:
https://connect.mayoclinic.org/discussion/i-have-mgus/

Other members who have or have had MGUS besides @pmm, are @teedlum @gingerw @michey @2012can @dianegrant and many other members in the various conversations.
Below are other links for information on MGUS and also some conversations regarding diet and MGUS.

https://www.mayoclinic.org/diseases-conditions/mgus/symptoms-causes/syc-20352362
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https://www.healthline.com/health/how-serious-is-mgus
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~What’s the science on diet and MGUS/SMM
https://connect.mayoclinic.org/discussion/whats-the-science-on-diet-and-mgussmm/
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~MGUS diet: Any tips on food to enjoy or prevent progression?
https://connect.mayoclinic.org/discussion/mgus-bgus-diet/

~MGUS and Curcumin/Tumeric
https://connect.mayoclinic.org/discussion/mgus-and-curcumintumeric/

Don’t go ordering those graver markers from Amazon anytime soon though, ok? ☺️