Help Us Please

My partner, F25, has been having issues with the following symptoms since July 19th, she took 4x Aspirin (75mg) and 9x Naproxen (250mg) with Omeprazole to protect her stomach and very little food to try and treat a headache she was having, since then she's had:

-Intermittent Tachycardia

-Lower BP than she had before (hovers around 105/70)

-Breathlessness

-Dizziness

-Heart/Chest pains that moves into her back

-Back pains

-Intermittent reduced urine output

-Intermittent thirst

-Lower body temperature (35-36°C)

She has been under investigation for some sort of GI bleeding but they haven't found anything and keep saying there's no evidence since her Blood Tests are always okay, her Haemoglobin level is good and her Urea level is low.

They won't give us any answers as to what's the cause for her symptoms though and keep saying it's anxiety and all in her head. What do we do? What do you think her symptoms show? She's had numerous ECGs which all show Sinus rhythm. We are at our wits end with everything and we don't know where to turn, we're both really concerned that she's slowly going into some sort of Hypovolemic Shock? We need answers any and all are welcome please help us!