Yeah I have shoulder issues as well, mine came about from a motorcycle crash and then I mucked it up again in my rugby days.
My first advice is to do Press Ups, lots of them. When things are going bad for me I will do up to 100 press ups per day.
Stretch out your shoulders before any hard work,
Slingshot, get one and use it
I do these three things and it has helped my shoulder immensely. My shoulder is so mucked up it doesn't grow muscle any more.
I'm not sure how your health system works over there, but over here we have no choice but to go to the GP and then sit around and weight for about 12 months until it has either cured itself or it is so bad it needs to be referred to a specialist surgeon for a proper repair. If you can get to the specialist first just do it and save your shoulder. If you are like me, my shoulder started to freeze up and became useless. Dont let a dodgy shoulder ruin your weight lifting.