Behavioral struggles with our 4.5 year old

Our youngest of two children will be 5 years old this summer, and is very definitely a spirited child.He is a high-energy sweetheart a great deal of the time. Very socially outgoing, very chatty, super curious about all manner of things. He's in kindergarten/pre-k, and does very well there, and has no issues according to the staff.But the evenings, and sometimes the mornings, are absolute hell in our house. I know bedtime is often a combat zone, but we are really struggling with how to weather the storm, and to be good and effective parents.He seems to spiral. He rarely just gives us a straight up "no", instead he hems and haws and fiddles around and only eventually after we've given lots of "extra time" and repeatedly asked - for tooth brushing, or heading to bed, or in the morning just to bring his cereal bowl to the kitchen - it ends up as a lying-on-the-floor, crying tantrum.I'm aware that this is not unusual, but the problem we have is that he becomes literally inconsolable. We were spoiled to his older sister, at this age would fight about things but we could eventually reach a compromise. Not so with my son, who I believe would let the house burn down around him sooner than agree to anything that we've asked, at that point.We've tried literally everything that I can think of. Carrot and stick. Removal of privileges, offers of privileges, pleading, bargaining, threatening, distraction, time outs, parental time outs, even spanking, which I'm not proud of, and is completely ineffective.My spouse is at her wit's end. Our daughter is traumatized by the screaming fits. I'm at my wit's end. And he seems Jekyll and Hyde about it. Sweet as a peach one moment, and a screaming dervish the next, and then back to sweet -- and asking for a treat or privilege as though we'd not spent the last 30 minutes fighting about buckling into the car-seat.My spouse has been reluctant to discuss behavioral issues with our pediatrician, and seems very much against the idea that this is anything other than normal behavior -- though by the end of the night she's in tears over the struggles.We've got a couple of books about spirited children, but nothing we've read or tried has helped us. I'm working on getting an appointment with the pediatrician to discuss, but I wanted to get some feedback from other parents.The constant fighting with him has reached a point that I dread evenings, because I know that we're in for an hour or two of constant screaming tantrum.It is really difficult to get him to nap, so he only gets an afternoon nap some of the time. We have a pretty consistent bedtime. His diet is okay. He's proven that he'd rather tantrum to the point of throw up than to eat anything other than chicken nuggets and tater tots.Suggestions welcome, but mostly I'm hoping to hear either that this is just the way some kids are and that maybe he'll grow out of it, or that the behavior is abnormal and we need help/therapy/medication/etc.Thanks! via /r/Parenting http://ift.tt/2ppvRwk