I can't take it anymore....

For the past few months I have had a rough relationship with my stepson (thankfully it's gotten better). I am in a place as where I just can't win. I have seen women on here tear other women down because they are stepmother but have stepped up to the challenge and be that mother the child needs. A lot you don't understand how much that support means to a child because I basically grew up without a mother. I have a mother yes, but I wasn't given the live and support of one and it tore me apart.... I had no one else and it was hard growing up without that motherly love and support and often a lot I cried myself to sleep and fell I to a deep depression. To those women who are stepmothers and are filling that part because they want to and not because they have to that is what a real mother is. Anyone can give birth and carry a child for 9 months but it takes a real woman to be a mother. I am in the same boat with women who are stepmothers and fulfill a motherly role and are insulted, yelled at, and told that it's really none of our business or concern and we have no right to claim a child as their own because of what the majority of society thinks. For women who say step mothers aren't real mothers please rethink that. I am a step mother who holds their child crying for hours because his actual mother decides when she wants to be a mom and when she doesn't and forgets about him. I make sure he always has food in his stomach and of it comes down to it I make sure he eats and I can't. I spend my last penny on this child and she barely even contributes just a pair of expensive shoes every 5 months. I make sure he gets to school every morning and that there is someone home for him to come to when I have to work. I make sure that his homework is done and that he is responsible. I take every evening out of my job to wish him good night and tell him I love him because I am his support. I am unappreciated, I am here 34 weeks pregnant and taking all this on and I have been doing this for 4 years. I am told that I am appreciated some of the time by my husband, but it's people who say you're not their real mother, you're not this, you're not that who tear me down for.giving a child love and everything they deserve and I hear it everyday to the point where I sit on the bathroom floor crying. I was even told that my son's mother should be called mom by my daughter because it's only fair when in all reality it's not... my son is lucky to have 2 mothers yes, but only one of them is doing the job. My daughter only has one and of it came down to.my husband leaving me and marrying someone else and that woman loved my daughter and showed her the love and compassion of a mother then she would have 2 also... but she is just my son's mother..... I am tired. In all reality I want to disappear because live with the people who tell me those things and I have no choice but to be around them and I am in my own house... what can I do?