A need to breathe deeply?

Today and for no reason that I know and for about 15 minutes I had to breathe very deeply. I wasn't having an asthma attack, nor was my chest struggling in any way. I am feeling unwell though, it's like being in withdrawal but there is no reason for it as nothing can be making me in withdrawal. I am on medication and have been for 7 1/2 years and have been taking them as I should. Another symptom is excessive tiredness. I'm absolutely shattered but again I do not know why. There is no reason that I know of for it. I have been asleep almost 24 hours (apart from my alarm waking me for pill time). Although I know I could easily go to sleep I'm resisting for now. I also have PTSD. I thought about phoning 111 but I think I'll give my GP a bell in the morning. If anyone has had something simpler or any idea what might be going on please feel free to tell me. Cheers

ive had similar symptoms