Honestly, I would start all over again. Go VERY slowly. Don't blowdry him after every bath. Simply start by giving him a bath, and then putting him into the bathroom but letting him just explore, sniff, and be happy. Don't even bring out the blowdryer. Just get him used to the fact that after bath = going into bathroom. Give him many treats and praise while in this bathroom. Make the bathroom a totally happy place. Do this a few times a day if you can or need to.
After a week or so of making the bathroom a happy place, bring out the blowdryer but don't turn it on. Put some VERY high value reward treats around the blowdryer and don't touch your dog, just let the dog take the treats. Then put the treats even ON the blowdryer so he has to touch it to grab the treats. After a few sessions of this, he should begin seeing the blowdryer as a treat-giver basically, lol. Bring the blowdryer out whenever you are doing
good things... in the kitchen, going for a walk, getting food. Just get him accustomed to being around the blowdryer. You wanna make this as much of a positive experience as you can.
After maybe 2 weeks or however long is needed of this slow re-introduction to the blowdryer... begin turning the blowdryer on, but don't blow it at him. Just leave it on so he gets used to hearing the noise for a little bit. Let him know that just because the blowdryer is on, does not mean he's automatically gonna have that scary thing on him.
I think just patience and positive reinforcement will help this.
A blow dryer can be a scary thing to a lil' pup, the noise, it's something new, the air, etc, so you don't wanna be forcing it on him or he will probably never like it. You don't want to let him get away with acting like a fool either, so just a firm 'no' should do when he does what you don't want him to. It sounds like fear aggression to me, so you just need to prove to him that it's not scary and he has nothing to be fearful of