Thyriods symptoms and conditions

Hello... I started taking Levothyroxine last July for slight hypothyroidism. I felt great for the first 6-7 months, but then in January the problems started for me. I was getting severe anxiety which the doctor said was stress and he also thought I was depressed. I knew I wasn't, but he put me on Ativan and Prozac. The week I took prozac was the worst week of my life. I thought the effects I had were from the prozac, but now I know now it was my thyroid spiking, which the doctor never checked my levels during this period. My heart rate doubled, I had insomnia, was gagging, sick, felt like my body was on speed and wanted to die. I was prescribed a beta blocker for my anxiety previously which I had never taken, but decided to take when my heart was racing, which helped me feel a bit better for the week, but I knew something was wrong. I had this happen again recently for about a week (and I was on nothing but levothyroxine). I know what anxiety is and I have never had anxiety or depression my whole life until these episodes that happen when taking this medication. By the time I went to the doctor to get labs done, I had been feeling a bit better and he said my levels were fine. I am now wondering if it's side effects from the meds or if it is spikes in my levels making me hyperthyroid instead. All I know is that I cannot live like this!! I have a 3 yr old and I need to be happy and healthy like I used to be before this medication... no more heart racing, racing thoughts, anxiety, and insomnia. Please help!!