only buy vegan food so I’m never going to be low-carb,

It's still possible! https://www.dietdoctor.com/low-carb/vegan

high cholesterol

This could be a early indicator of cardio vascular issues (especially if you also have hyper tension). Next time you go to the doctor ask to get a CAC score (calcium imaging in your arteries), its relatively inexpensive (100-200 USD) and tells you about your immediate cardiovascular risk. Alternatively you could look at your TG/HDL ratio as a indirect proxy to determine if the cholesterol is pattern A (non-damaged)