She’s away for lunch, getting her nails done etc and has no concept of what its like.
Of course she knows - she raised you. When your children get older, you get time for going out for lunch and getting your nails done, she's not being selfish by enjoying the freedom she now has.
I get that it’s not her responsibility but I just feel like everyone’s kind of forgot that I’m dealing with all of this
I don't mean this as harshly as it sounds, but... it's not anyone's job to remember that. Millions of people are parents, and (unfortunately, when you're absolutely drowning in it!) it's not especially unusual or special to be dealing with lots of stuff, and it's not anyone else's job to keep that at the front of their mind and help you out.
Just feel like I’m trying to do so much and no one cares enough to even offer to help
I can hear the stress and exhaustion but instead of framing it as nobody cares enough to help, think of it as - it's nobody else's job to help. That sounds horrible, but instead of feeling like you're waiting for support you should have that isn't forthcoming, evaluate what you (and DH) can do and work with that - then you're not feeling like you're getting something you should be and you're looking at the situation as it is which is that having a small baby is expensive and time consuming and that unfortunately not a lot of the options to help - nannies, expensive paid childcare, not working, splitting part time hours with DH to share the load - are ideal. It's shit and this country has such expensive childcare that I sympathise, but that's what the deal is and you just have to find a way to make it work.