Just some observations - I am getting the impression from your last post that maybe you are not allowing yourself enough down-time to relax. It sounds as if you have a very busy life ! Your working out with weights sounds busy to me. FWIW I do 30 press-ups and 50 sit-ups every week-day, and about a 10km run (jog) every week, sometimes twice a week. This keeps me nicely toned for seemingly not much effort. I do the daily exercises when I get up, and need no equipment for them, and no booking or gym time - and they only take me about 5 mins per day. That regime is quite gentle and not demanding, and is all I need to achieve a good body shape. I would definitely buy some proper running trainers though - you don't want to cause your joints any problems by running in the wrong footwear.
Your reliance on your phone to relax - I think that is probably having the opposite effect. They say that use of screens in the evening can make the body stay awake. I would try having time with no screens at all to relax properly. Leave your phone at home when you go out for a jog or a walk.
I personally find that when not at work; if I go the sleep much after 2300, I pass a threshold and my brain then stays awake - obviously a learned response to years of night flights, when my brain goes, "Oh, are we staying awake tonight? OK then." So maybe try going to sleep earlier in the evening and no screens beforehand. The blue light from the screens and the content you are looking at before trying to sleep might well be keeping your brain active and causing your sleep problems. A hot bath and a hot milky drink can help induce sleep.
Sitting around at home is not the same as sitting in an airliner cockpit - in the latter there is the constant low-level stress that tdracer spoke about, with moments of high stress during take-off and landing. Also the noise levels in a cockpit are very fatiguing. Interesting that train drivers do not operate for more than 5 hours before having a 30 minute break.
Regarding hot drinks - if the water has been boiled, it should be safe enough. Britons were less prone to health issues from bad water in the past, because they boiled their water to make tea. (Cold tea sounds horrible!).
I make healthy bread (with a machine) and healthy sandwiches to eat at work. Or salad in a Tupperware box - cut the salad up with kitchen scissors, which is quick and easy to prepare - and easy to eat with just a fork. I often put frozen cooked prawns in. The prawns act as ice to keep the salad cool in my bag, and when I am ready to eat the salad some hours later, the prawns have defrosted. That way, least I know what is in the food I eat.
Yes, you should see a sports physio to sort out your arm - might be able to get that under your airline health insurance.