Hi Bassiette,
I suggest you simply ask your doctors what kind of food you should avoid. I had high cholesterol levels a few years ago, and I was told to avoid full-fat milk and full-fat yogurt, then cheese, butter, red meat (that is veal, pork, mutton, beef…), fat fish (salmon, mackarel, tuna), and all kind of animal fat. And to avoid every kind of fat used for cooking. I mean: I could use olive oil, but not for cooking. I could only add it on food that had been cooked without using any fat. Only two eggs a week were allowed. No cream, no margarine, no mussels, no sausages, no ham, no bacon. I had to be careful even with nuts, hazelnuts, pistachios and seeds in general: only a tiny bit were allowed every week (some 30 gr). Of course no mayonnaise, no salad dressing sold in bottles, no pre-cooked plates, and no pizza.
Good foods were: low-fat milk and yogurt, then cottage cheese (but no other kinds of cheese, as I said), then 'white meat' (chicken, rabbit, turkey), and lean fish (ask you r doctor, as I don't like fish very musch and can only recommend codfish and trout… but there are plenty you could choose from) and then vegetables, and home-made bread (I bake it myself without using fats like oil or lard), and pasta, and fruit.
One important thing to bear in mind is that one should learn to cook without added fat, especially no cooked (heated) fat. I used vegetal stock instead of oil, or simply water, and sometimes wine (but I found wine to be a little too hard to digest). I steam-cooked nearly everything, or I baked in foil the fish (you wrap the fish in a foil of aluminium together with a little garlic, salt, pepper and some herbs, then bake it for some 30 minutes depending on the fish size).
Anyway, ask your doctor, who will certainly suggest a wider variety of good foods and good ways of cooking.
I can only add this: I discovered that cholesterol levels vary wildly according to seasons. To some extent, that is true for everybody, but as for me it was not a matter of 5/10 units higher or lower: it varied (and it still does) by 50/60 units depending on the time of year.
So perhaps you could try and test what your cholesterol level is, at different times of the year. Maybe you will find that in spring/summer you can relax a little, while being more careful in winter.
I wish you all the best and hope I wasn't too boring with my lists and suggestions.
Be well and take good care of yourself!