Two weeks ago, I decided to move about an hour away to get a job and get a place to live for me and my son. His father agreed to temporarily take him for 3 months or so, so I could get an apartment. My mom originally wanted to keep him for me, but because he is his father, I thought that was best. He now thinks that our son's original diagnosis of Bipolar is wrong, yet he won't take him to another doctor for a second opinion. He won't even make a phone call to take him in for a 6 year check up at the doctor. I have raised him until 2 weeks ago, and he knew it was not permanent. He is now threatening to say I abandoned him. I have seen him since I have moved and I talk to him regularly. He is threatening to take him off his medication. I was told by cps that he had to be medicated for his bipolar disorder and that it was considered a mental illness. He has been to 1 or 2 of the appointments out of 6. he has no job.. and when he does, it's for a few weeks... he is behind in child support and hasn't even attempted to get a driver's license or a ged. The only good thing I got from him was our child. I am wondering if I can request that my mom have temporary custody of my son on the grounds that his father is incompetent to care for him medically? I see him not giving him his phsyciatric medication as neglect. He, our son, has a formal diagnosis of bipolar 1 and adhd and he wants to end the medication.
I have a job, I plan on being out on my own in 2 months... and he's living with his parents with no job or education. I am afraid that if I leave this job to move back and take my son back, I won't be able to support him the way I should so I want my mom to have temporary custody of him until I am in my own apartment. How would I go about getting this done, if even possible? I live in Texas by the way

Find a lawyer... most lawyers don't charge anything for the consultation visit. Ask the lawyer how to go about giving temporary guardianship to your mother. You never stated if your mother was willing to take your son for the few months, but assuming she is, giving her temp guardianship will allow her to sign papers at the doctor's office, school and hospital should he need to go for any reason. She also may be eligible for Kinship Care - a monthly supplement from the state, however, you would be asked to pay Child Support if you go that route. Before going into court, have all the missed appointment information together and with you - getting a note from the docs office ON THEIR LETTERHEAD stating the appointment days and which ones where missed will help in your claim that the father is not attending to your son's medical needs, which will be helpful in placing him with your mother.

Best of luck to you!