Very mild chest pains, dizzyness and tremors. Please would someone give me some advice or maybe some possible answers?

Hi. I'm new to this so I hope I find some guidance or answers.

I experience very mild pains in my chest, it feels more like pressure rather than a pain to be precise. I get it in the left side of my breast and what feels like the centre of my chest between my breasts. Sometimes I feel an odd pain in my left upper arm (almost under my armpit and shoulder) and sometimes a very very mild pain feeling in the left side of my neck. These pains come on for maybe a couple of minutes and can continue for 3-6 times a day. I am not stressed or worried about anything so I think maybe this is something else. I also experience what I believe can be described as tremors in both of my hands. Sometimes the tremors can be quite severe, and sometimes I can feel this in my legs and it can also travel through my arms. Once I had it in my lips and tongue. It makes me feel like jelly and quite weak. I do not always experience the chest pressure pains and tremors at the same time. As well as this, I always seem to be so tired and unmotivated to go out because of this. I work 13 hours shifts 4 days in a row so perhaps im working too hard, but perhaps not. A few days ago, I felt like jelly and felt like I was going to pass out so I had to sit down for ten minutes. I think this was because I hadent eaten much that day and I had quite a busy day. I thought I should mention though incase there is a link somewhere here. I have recently started to get heartburn alot after eating. Maybe im eating too fast. A few months back, I had an ECG and bloods taken and they said everything is normal. I think that some of these symptoms are to do with health and lifestyle, but I have had these kind of chest pains for around 4-5 months now.

Rox xx