No Matter What I Do - White Smoke

I have a Cheyenne. I love it except for the fact that 95% of the time I am smoking with the fire door open in order to keep my fire alive. I've watched all of the videos, I am using seasoned wood. I want to cook 225-250 but end up having to cook from 250-275 since I cant really burn anything with the door closed.
I start with a chimney full of oak lump. I then toss it onto the grate. Usually start with 2 pieces of hickory, I have been buying the bags of hickory splits at Home Depot since in Southern California it's very hard to come by. I do have some oak but it's too large, Im going to have to get a saw to use it.
So I let the logs catch, close the top. Leave the fire door open for a bit, usually I start to close it a few inches every 5 minutes until the door is closed then I back down the temp. Usually when I first start, I can keep the white smoke away since I let most of that happen before the logs catch. So usually I'll get the door shut and it will be around 230 or so with the vent 3/4 open. It's great ! I leave it for 45 or so until it gets down to 205.
This is where the fun ends. I stick a couple of splits on top of the firebox to heat them up. So I open the firedoor and toss them in. Usually I have to open the top of the firebox too in order to keep the white smoke out of the cook chamber. So it catches, seems healthy, so I close the top of the firebox and do the same as I did before but this time, even starting to close the door partially, I start to get smoldering. Even after 15 minutes of fiddling with the thing when I think at least by now everything is caught, closing the door, white smoke within a minute. So I end up having to baby the thing and ultimately leaving the back door open until I need more wood.
What am I doing wrong? The wood is dry as can be, and when I put it in, after being on the firebox, its too hot to touch for very long so I use tongs. I tried the method shown here on video, keeping fire on one side and a split on the other. Trouble with this was for me burning one split at a time, I hardly ever had enough coals after 1 log to keep my temps up for another one.
The only successful smokes I've had have been at 275 with the back door open the whole time, having to reload every 20 mins, which honestly isn't very efficient. Am I not using enough lump to start with? It's really frustrating ! I want to do a brisket but I dont think there's anyway I can baby this thing sitting in front of it for 12 hours. Most of what Ive read is once its going, reload every 45. That sounds great to me ! IF i wanted to sit in front of it id have just bought an OK Joe smoker
Thanks !
I start with a chimney full of oak lump. I then toss it onto the grate. Usually start with 2 pieces of hickory, I have been buying the bags of hickory splits at Home Depot since in Southern California it's very hard to come by. I do have some oak but it's too large, Im going to have to get a saw to use it.
So I let the logs catch, close the top. Leave the fire door open for a bit, usually I start to close it a few inches every 5 minutes until the door is closed then I back down the temp. Usually when I first start, I can keep the white smoke away since I let most of that happen before the logs catch. So usually I'll get the door shut and it will be around 230 or so with the vent 3/4 open. It's great ! I leave it for 45 or so until it gets down to 205.
This is where the fun ends. I stick a couple of splits on top of the firebox to heat them up. So I open the firedoor and toss them in. Usually I have to open the top of the firebox too in order to keep the white smoke out of the cook chamber. So it catches, seems healthy, so I close the top of the firebox and do the same as I did before but this time, even starting to close the door partially, I start to get smoldering. Even after 15 minutes of fiddling with the thing when I think at least by now everything is caught, closing the door, white smoke within a minute. So I end up having to baby the thing and ultimately leaving the back door open until I need more wood.
What am I doing wrong? The wood is dry as can be, and when I put it in, after being on the firebox, its too hot to touch for very long so I use tongs. I tried the method shown here on video, keeping fire on one side and a split on the other. Trouble with this was for me burning one split at a time, I hardly ever had enough coals after 1 log to keep my temps up for another one.
The only successful smokes I've had have been at 275 with the back door open the whole time, having to reload every 20 mins, which honestly isn't very efficient. Am I not using enough lump to start with? It's really frustrating ! I want to do a brisket but I dont think there's anyway I can baby this thing sitting in front of it for 12 hours. Most of what Ive read is once its going, reload every 45. That sounds great to me ! IF i wanted to sit in front of it id have just bought an OK Joe smoker

Thanks !