You do count. And you deserve to be treated so much better than this.
I know it would be difficult, but I'd suggest you buy little, token gifts for your family, and use what you save to get yourself a real treat.
My experience of this is nowhere near as bad as yours, though I am sure I am not the favourite daughter - that is my younger sister. I still remember, with a pang of pain how my 18th birthday present (touted as the BIG birthday) was a clock radio that cost about £20, whilst, for her 18th, my sister got a musical instrument that cost about £250.
I am 100% sure my mum loves dsis best, and always has. When I was at university, I was a pretty good singer, and did solos with the university philharmonic orchestra and choir - and my mum never once came to hear me. Dad came - and all she'd have had to do was get in the car with him, but no.
Or there was the time when I was a teenager. We had a very old and temperamental immersion heater, so we had to share bathwater - dsis and I shared, then later dad and mum shared. Dsis and mum always went first, and got the hot, clean water. Dad and I went second, and got the cooler, grubby water.
Initially I accepted this, because dsis went to bed earlier than me, so the payback for having the second bath was staying up later. But when we were both teenagers, we had the same bedtime - so I went to mum and asked if dsis and I could take turns at having first bath (we only had two baths a week) - that way I'd get to have the hot water once, and dsis would have to do the clearing up at the end of the bath - rinsing it out, hanging up the bath mat - nothing terribly onerous. But my mum refused point blank. She said there was nothing wrong with the slightly used bath water.
Dsis is still the golden child. And I am 52, and it still hurts.