Hi everyone. I’m a newbie to the forum and I could use some advice. A month ago I purchased 2 male Gouldian finches (they are only to be kept as pets for my personal enjoyment

). I’m having an issue with one of the finches. Originally I had the cage located in a window. However, in order to open the shades I had to lean over/around the cage to reach the pull. About a week after having the finches, I reached around the cage and inadvertently surprised one of them. He was sleeping and I startled him awake so I assume this is a type of night fright??? Since that day, he has begun acting strange. I’ve done a lot of research and I’ve concluded it looks like Stargazing. He throws is head really far back until he almost falls off the perch. There’s definitely no signs of Twirling. Also, he still has full control of himself while he’s doing it because if I talk to him, he immediately stops and looks at me. He rarely does it during the day. It seems to be at its worse in the evening (around the time when the original fright happened). Other than that, he’s a happy little bird singing, eating, and flying around his cage. I’ve recently moved the cage away from the window and given him a light instead so I don’t have to reach around the cage anymore. I’ve also separated him from the other finch because I’m worried the other one may start to bully him. I purchased Trimethaprim Sulfa to keep on hand in the event he actually starts Twirling. It’s been 3 weeks and the behavior is no better. He has difficulty settling in and going to sleep because he keeps himself awake throwing his head up. Can anyone give me advice on what I can do to help him get over this? I only have a daytime bird light, should I invest in a nighttime light? Or maybe start covering the cage at night? Should I give him the Trimethaprim Sulfa just in case it’s the start of Twirling? When should I consider re-introducing the other finch?
All advice is welcome. Thanks in advance.