Hormonal coil (IUS) and irregular periods

I've had the mirena coil for four months, I'm still bleeding irregularly (period every 8 days) and lots of spotting. I've been dizzy for months, I'm feeling very low, I have water retention and a lot of lower back pain that feels like a pinched nerve so I'm battling to concentrate on work. I really want to have it removed but I'm terrified of going back to the alternative of extreme heavy periods that made me anemic.

I've had great success with a Mirena for treating jawline acne, after getting it to prep for going onto Roaccutane it actually cleared my acne up amazingly and now I just get the odd spot every month when I'm due on. I get irregular, yet light periods, and occasionally some spotting, and overall my period cramps have been lessened. My sex drive is not what it is when off hormonal contraception, but as I've been on hormonal contraception my whole adult life, bar a couple of years here and there, this hasn't been an issue overall. I have put weight on gradually, but I've also aged (now 34), so its more likely to be metabolic changes rather than a side effect. The only thing I would say is that the coil itself has moved twice, resulting in removal and replacement (I'm waiting for another removal, and will likely explore pill options again as its just too painful getting it replaced every 2 years!). It should last 8 years, but for whatever reason, maybe my anatomy, mine moves to be too low, and then the long process of getting it checked, ultrasounds, appt waiting times for removal, and everything else, means its not something I want to continue using at the moment. Overall though, it has been a really good method for me, and just because mine hasn't stayed where it should be, doesn't mean someone else won't have a good experience, its probably down to my anatomy only!

I was very worried about trying this method as I’d not used hormonal contraception before but overall it has been positive. The insertion was quite painful but not unbearable. It took about a week for me to recover, with me having to stop exercise for that time and then slowly increase again. Bleeding has been the most annoying part as my periods are very irregular now (previously they were regular as clockwork) and I have light spotting for up to a week before each period. But it’s getting slightly better each month and I’m hoping I’ll be one of the lucky ones who eventually gets to little or no bleeding at all. I’ve suffered no other symptoms of note.