Why does this bother me so much???!!?

So a lil info about me I'm 17 gonna be 18 in may and When I was younger I used to get nervous and feel uncomfortable around people so my mom got help for me and I started getting SSI checks every month and when I turned like 12 I started feeling like a loser for getting checks and I hate the word mental health, I'm not mental I'm a very smart girl I have overcome my shyness and nervous so much and I even have a boyfriend that I love very much and friends!!an anyways today when I woke up my mom told me she got a letter that we needed to fill out since I'm gonna turn 18 and the SSi people wanna know how I'm doing? and while we were filling out that letter I started crying alot cause all thoese questions in that letter made me feel like there saying I'm mentel and stupid! And I told my mom I didn't wanna fill out that letter anymore and she started asking what was wrong why I was crying and I told her and she's like your not stupid it's just how the SSi is and she said If you don't want this anymore we can just rip the letter up and forget it since you have overcome so muh since you were younger & so she ripped the letter up and it felt great but I don't understand why it bothered me so much? Sorry this is kinda long,