Pickle......Firstly there is no interaction between statins and other drugs. Some brands of margarine contain them!
You need a blood test to determine your current cholesterol levels...ask for one, it is your right.
If they are high, then one of two things need correcting ,which a good doctor will be able to tell you by correctly interpreting the results.
I say correctly because my GP told me I needed to just change my diet and that would do the trick...............a year later it had gone up to 7.4. Not trusting the NHS I paid for a private doctor ( and test ) in South Africa when on a visit....a real eye-opener I might add. He told me any doctor worth his salt could see from the results that my liver was producing far too much cholesterol and no amount of diet change would help. Today my level is 4.2 By the way the acceptable level is 4.5 and NOT 5 as the UK will tell you.
Good luck