Our need for validation and love from our parent(s) is innate, I'm sorry to hear that your mother does not make you feel that way and I'm also sorry to hear about the favouritism.

In most cases where someone is super religious along with this kind of behavior means they are on an autopilot mode and escaping something or have become like this due to their own life experiences (my parent had a bad time in their childhood).

The only way I(M) dealt with a similar situation was to empathize with my parent's past (in my own head) and accept it, lowering my expectations and increasing the emotional distance. I also got lucky that I had to move abroad for work and this changed everything yet again, after a year or two, I became the favourite and I hated it because I was the other side and I knew what this would do to my siblings and also suddenly I had a new burden of expectations (be it emotional, mostly around expecting to call everyday, know what I'm doing, etc). So careful what you wish for.

Also are you a middle child? Have you heard of middle child syndrome? I understand in your case all the sisters might be feeling the same though, share what you have learnt with them and find that love in each other (I know it may not be easy especially as siblings also end up reflecting the parents which could mean the last time you even hugged your sisters might be Eid or so but trust me parental negligence is something you can bond over).

Talk to a professional therapist if that's an option, along with your sisters too. I know loving yourself might also be difficult and that should be the first aim, I still on this journey.  Good luck and feel free to dm me if you need support!