Hello, I understand that my hand needs to be trained in order to comfortably stretch my fingers to the point where I can reach the individual frets, however my hand is making it impossible. I try my best to match the technique in the lessons but for some reason my fingers will not stretch apart AT ALL. Then I got the idea to use my other hand to force them to go to their own frets in an attempt to stretch them out but doing so causes my other fingers to slide down the neck due to my unflexibility. When I use my other hand to hold the other fingers in place the result is intense pain and the inability to hold the position for more than a second.

Is this just because I am holding the guitar incorectly after all or do I just have to keep forcing my fingers apart until I can eventually do a warmup? Thanks in advance.