scared my antidepressants stopped working

So, I’ve been on mirtazipine 30mg for about two months now, and I think it’s starting to stop working. I’m still having anxiety symptoms, and I’m getting the “I’m never going to feel better again” and the “I’m not good enough” thoughts again. I’m also crying again. I’m not only worried that my medicine has stopped working because I was feeling so much better for a while, but I’m super scared that’s it not working because I have a underlying disease that’s making it stop working. I had multiple tests on my heart in FEBRUARY of this month, and it all came back normal. I also had a CT scan of my head in July, and multiple blood tests done it July to rule out any causes of my depression and anxiety.. however I’m still worried that I’ve developed some disease since then. Does anyone have any advice??? I’m so scared of coming off of the medicine because it helps me sleep, and I’m so scared that I’m going to relapse. Please someone give me some advice😭😭

I should mention I’m only 15 

Hi Shelby - with anxiety unfortunately it comes and it goes and when it comes we tend to overthink things. That’s anxiety for ya. You need to know in your head that it always passes and you will be ok. If you have an instagram please go and follow @anxietysupport. She’s awesome and also struggles with what you are going through. I would also recommend seeing a therapist weekly until you can control it on your own and you WILL get better. I promise. Reach out to me anytime ok! Xoxo

Hi I've had anxiety for 32 yrs plus depression.im on mirtazapine 45mgs and been on it for yrs.its not wise to come straight off meds.why do u want to come off them? Some people have to take them for life like myself.its not wise to come off them totally but to reduce gradually.i found it worked for first few weeks or so as it helped me to sleep but I have now got used to them and they no longer make me feel sleepy. Eat Well, keep hydrated and look after yourself.do you work? I've been in and out of work too.i find it difficult to interact and can't take information in when anxiety is really bad.affects my memory and concentration too. I totally understand how you feel.take care x