Help i am going to lose my mind

Hello, i am new to a support group, and in need of one BAD. My son is 4 1/2 and was diagnosed with ADHD about a month ago, we had been seeing a phsyciatrist for about a year for seperation anxiety and continued after that seemed to go away for behavioral problems. My husband is active duty Air force and we moved from California (about an hour away from grandma and grandpa) to Washington. My son did not adjust to the move and we thought his behavior was a result of it. Now that he has been diagnosed it seems harder to deal with, i am dealing with my own fears of raising an ADHD child along with rethinking how to deal with him. We reluctantly put him on meds today, he is taking ADDerall. We weren't expecting a miracle just some relief, but his behavior today was horrible, my husband and i don't know how to handle him, we have lost all patience's with him and have to try really hard to not lose our temper and yell at him. we starting giving him melatonin 1mg at night so he would go to sleep, that was a miracle he would go right to sleep. we notice on days he gets alot of sleep he is better behaved, as with most children. He is a whiner,,,constantly whinning, crying arguing. i have tried all different kinds of disciplline, it would work for about a week and then i would have to try something else. we have a 2 year old daughter and she is starting to act out, i believe because of her brother's behavior and all the yelling we do. my home use to be a happy one, my mother has come to live with us also. My husband is retiring in october and we are moving back to California, which i think will be better for my son, or make things worse with another change in his life. My home is now tense all the time, my husband and i seem to argue more now about discipline for both children and we are both exhausted at the end of the day. I just don't see a light at the end of the tunnel, i am so frustrated and don't know what to do anymore. Thanks for listening!!!!