Possible med interaction

18F (trans male so please be respectful) 230lbs (loosing weight slowly) Current medical conditions: Hypertension, chronic migraines, insomnia, chronic joint pain, sudo seizures, recurring hemolytic anemia, tachycardia, gastriparisis, GERD, multiple phycological diagnosis aswell Medications: Propranolol 10 mg twice a day, lamictal 200 mg, effexor 75 mg, sprintec, Erythromycin 125 mg three times a day, Vitamin D once a week, potassium and magnesium once a day, pantoprazole 40mg, NEW- doxepin 3mg My Hypertension and tachycardia are under control and have been doing great recently! My last Hemolytic anemia episode was in March of last year (had blood taken yesterday results were wonderful). So I got put on doxepin 3mg a few days ago and got it filled yesterday, last night was my FIRST time taking it. First of all it did not help get me to sleep nor keep me asleep, but what is worrying me is how I woke up feeling. (Finally fell asleep at 7am woke up at 11am) I was informed that there can be a slight interaction between Effexor and doxepin but only if on a higher dose. (The reaction was described only as a fluttering feeling in my heart) And was reassured that a racton was not going to happen due to the doxepin dose being low. Was also not informed on what to do if this reaction occurs. And last night I had noticed that my muscles were oddly stiff, and causing me some pain and to be very uncomfortable. Along with my heart fluttering. I was finally able to sleep and only slept about 4 hours. I woke up with the muscle stiffness a bit worse, and a horrible muscle cramp in my leg. I keep having muscle cramps, which is not normal for me. And ofc I thought "maybe I'm a bit dehydrated", but I drink a ton of water, I am urinating regularly, my urine is not dark whatsoever, and my mouth is not dry. I of course did my own research, as I always try do, due to my list of illnesses and having a history of weird reactions to medications. And I read that Effexor and doxepin can cause a much higher chance of serotonin syndrome, which of course I am worried about as I was not informed that was a risk. I am not worried to the point of going to a hospital, but I am wondering what others opinions are. Am I overreacting and being paranoid, or is this a normal reaction for the first time taking doxepin?