What Would You Do In This Situation? 😒

So this is going to be long just a warning because alot of people complain saying posts are "too long " just leave now if youre the type of person that doesnt like to read long posts. 
I just want to share something that I know is wrong but i'd like to hear opinions on what you would do in my situation. 
Well , basically my grandma has taken care of me all my life since my mom gave up her rights. To this day shes always there for me and helps me out with whatever she can & im really grateful for that. 
Well heres the thing, a month 1/2 ago I recieved this letter and I didn't understand what they were trying to say so she showed my uncle and it was a letter from financial aid saying they had money they owed me it was almost 3,000 dollars it said to fill out the paper and send it to them so they could mail me the check well both her and my uncle told me to not tell my boyfriend since hes the type that if he knows I have money he will ask for stuff or get us to spend it on something (i'm easily convinced) they told me " youre not married so you dont have to tell him anything only when youre married you have to tell your partner" . Well, we recently got married last month (not for that reason)
And I recieved the check last week but my grandma got it and she kept telling me lets go to the bank so I did. Since my husband knows my chase username and password for my account and I know his, she told the bank teller if he could transfer the money into her account because they said something about I wouldn't recieve all the money until the next day. Okay so, she told me she took out $600 
and I had to take my kitten for his shots and do my taxes so what shes been doing is giving me the money for a example, she gave me 50 for my taxes and 40 for my kittens shots and what I find stupid is how everytime she gives me the money she makes me sign off on a paper saying how much she gave me and for what. When I think she should be the one signing it -.- and well basically it seems as if she just wants to control my money and I hate it but idk how to tell her I dont like what shes doing ! Shes always been like that 
I hate having to ask her for MY money when I need something 
And on top of that its pathetic how she expects an explanation of what I want to spend it on. 
I shouldnt have to explain myself and I definitely should'nt have to ask repeatedly for something I want to buy with MY money. 
For example , i've been wanting to buy some extensions online and get my nails done for my baby shower this saturday, I also need to buy a dress as well as some nursing bras and some stuff for my hospital bag. 
Ive mainly been asking for money for my extensions and nails because I need a fill and a color change ( I asked 3 times already)  😒 but all she says is " youre due in 4 weeks you dont need to get your nails done anymore" and she expects my husband to buy me my robe , nursing bras and my hospital bag things. Like hello hes my husband not my
Slave. 
shit we bearly get by even though he makes 900 $ every 2 weeks. He told me he doesnt want me to work until the baby is about 6 months.  I feel like if I can help out and buy my own stuff then I should. After we had left the bank she had told me " I know youre married now but you dont have to tell him everything " like wtf why are you switching up your words of me telling him when we were married. She's holding back on giving me my money for my extensions and to get my nails done beause she says I should buy my baby a crib and she says shes waiting because my MIL said she was going to give us her sons crib. Its annoying because hello I have almost 3,000 dollars why cant I spend $ 200 on what I want ? theres plenty of money for both things ! 
Shes not the type to robb me or use my money however she does try controlling it . 
I really dont want to be mean but this is not right . Do I just say " I need 250 to buy myself things I need " or should I just demand for her to give me all my money ? 
What would you do ?Â