Boiler pressure

I need some advice please. I have no technical knowledge and i am a woman who also know nothing about DIY and is scared of gas things
I inhereted my boiler with the house, its about 7/8 yrs old now. When I moved in I got a gas man to come and give it the once over, as it had been fitted by the previous owners brother ! He took I look at it a groaned, the worst boiler possible ! Its a Heatline? The pressure kept dropping, he said that I needed a new boiler. Also the pipes from the gas meter to the boiler were the wrong size, if I remember he said they should be 22 and they are only 15 or 18, so they need to be changed.
I really cant afford a new boiler as I am on a limited income (very limited ). the last few weeks the pressure drops at night and to get the heating on i have to re-pressurise it in the morning. Its a bit hit and miss as the dial is broken. My heating is then on till 10pm and it is fine.

My question is, do I really need a new boiler, or is it possibe to repair this one.
It also takes me 20 mins to fill my bath with hot water as if comes out so slowly, is this related to the boiler? Good job I have an electric shower.

It's not possible to say without seeing the situation. The best way forward would be to contact a local Gas Safe engineer. If this boiler hasn't been serviced for all these years, it should at least be checked for safety.