Fracture humerous worried about going back to work

I saw the doctor  very quickly at the fracture clinic they are so busy he just looked and said we will see you in  six weeks and review treatment if it hasn't improved, and then he walk out, they are so busy , the nurse looked more sympathetic I told her about my job she said I can always get another sick note?. the dovtord just haven't the time to answer questions these  days .

I am panicking a bit, I spoke to my shift leader when I dropped my last sick note off and she did say she was concerned it was  full on Christmas period with lots of heavy goods ,she said she would decrease my hours for a while, the problem is I had a major ( this was a large one ) incisional hernia operation in July. I was recovering  from that and was due back to work a couple of weeks,   then I broke my shoulder . and last November I had an emergency bowel operation my bowel was strangled with adhesions so I had last Christmas off work, I push myself and went back to work too early which may of caused the incisional hernia (this is in other forum) so I felt guilty I picked a hospital that could do this operation quickly so I could be well and working over the Christmas  period I was beginning to feel a bit better when this happened if I go back to early and get sick or hurt my shoulder as the work is repetitive I will get a warning , I will probably get one anyway . I don't normally have any time off sick lol but three major things in a row all very painful, its taken it out off me emotionally and physically

Long-term disability??  You cannot receive a "warning" because of your medical condition.  

we haven't got a HR I live in Somerset  and yes they can its is their policy I have a doctors sick note, so most likely I will get a warning on my records as they will treat my time off sick this time as two different things which it is, I don't know what FMLA  is and if this is some sort of benefit I know people who are on universal credit and PIP which has been rolled out in our area and has cause people to despair that why I am so worried as I know how things can unfold,

Well, that stinks.  Do your best to keep communicating with your employer and your doctor.  YOUR HEALTH is very important.  You will find the balance.  You have had a rough go.  Do not give up.  Take it one step at a time.  It's temporary.  You will recover from all of it.  I live in the USA.  FMLA Family Medical Leave Act is federal protection in the USA from employer retaliation or termination due to a serious medical condition.  It saves your job, etc., etc.,  You are not paid unless you have sick time while on FMLA or a person could use short-term disability or long-term disability and you have paid into the disability categories.  In the USA, employers also have separate medical leave due to serious condition.  Last Jan-April I used 12 weeks of FMLA for injury/surgery/rehab without pay.  I returned to work while continuing rehabbing with a physical therapist after work.  The PT ripped one of my repairs off its anchors.  I had to go out on medical leave without pay AGAIN June 1.  I was not protected by FMLA, but as a teacher, the school went into summer recess the third week in June, and I rehabbed over the summer.  I returned to work August 28th.  Lots to think about but try not to panic.  Take it one step at a time.  Keep your chin up you need to focus on your rehab.  Fretting/anxiety may delay your rehab progress.  Sometimes we just have to trust and have faith that it will work out favorably.  Communicate with your employer - trust and faith - rehab and keep thinking positive.  You will be okay.

My arm is so weak, I can just about lift it about a foot from my body its a strange feeling.

I can lift it with my good arm, which I am doing as directed  but it hurts all-day after exercise .