Old blood on the depo shot

I’ve always had terrible periods and have been on multiple different birth control pills so my doctor recommended the shot I researched it although I guess not good enough now I pretty much decided to stop taking the depo shot the first shot I loved it I didn’t have any pain or bleeding for three months I was in heaven and I took a second shot it wasn’t till after I found all these horror stories cause I’ve had old blood coming out of me for about two months now some days it’s only when I wipe or spotting and other days it’s almost like my actual period but it’s super dark and a little thick my last depo shot was at the end of January but this has been a night mare cause I even get cramps again too and It’s also interfering with my sex life I just feel gross and uncomfortable and I was wondering if there was any way to make this stop or what I should do my doctor said it’s normal but I’d rather go back to regular periods than going through liners, pads, and tampons every day