Pls Help Me! 'My Wife Said Her Ex-Boyfriends are Better Than Me' - Young Man Seeks advice

I seriously need mature mind men opinion. This is a lady i meet managing in a room with her friends, i did my little best to rent an apartment for her. This is a lady i meet using Tecno java phone, i bought her her first android phone(Infinix). I never even propose wedding to her before she started discussing marriage with me because she is very sure i loved her. We wedded after 9months we met.(3years ago).
Four month ago, i wanted to help her apply for a job online which i have done to the stage of uploading credentials and i asked her to give me her credentials in order to complete the registration, but to my surprise, she told me she has not collected her certificate from the school she graduated from for the past 5years and she never bordered to collect it. I was forced to report her to her sister.
She latter bounced back on me with force, comparing me to ex-boyfreinds, asking me what did i even have that am doing shakara, that her ex is far better than me financially, that her ex rented 3bedroom flat for her then but she just choose to come to the one room i rented for her. so on and so fort.
And now, i have started thinking negatively towards our marriage and am very confused on reason why she would even compare her ex to me just because of this little matter. And how come her ex is better than me.
Thanks in advance for opinion.