It's unusual for side-effects to only become noticeable after this length of time. I was prescribed it but after a week or so felt like a zombie and so went back to my GP. I had to push though as the first telephone call I had, I got pushback. Went onto felodipine and no side-effects at all.
So, as others have said, go back to your GP. The posted question re statins is a good one. My cholesterol is marginally high but mainly due to high HDL (Ie the good stuff) and so the ratio is good. They keep trying to put me on statins but as I explain to them, I've run all sorts of permutations through the QRISK website. Dropping the cholesterol only gives a marginal improvement and so the risk of side-effects (at least IMO) outweighs the 'benefits'. QRISK lets you look at what your QRISK is compared to your cohort and what the affect of changing things like BP, cholesterol, weight etc will have. The trouble is that us chaps have two things that affect the QRISK an awful lot and over which we have no control and that is age and gender.