I am having little bumps on my butts, and my butts' texture is also getting worse. what should i do to make it look like my rest of the body?

Those bumps can be from several things. It needs to be seen. Is it an infection, dermatitis, ?

It is not feasible to provide a meaningful answer without examining you. If you have gained weight, that may be partly responsible. Low grade infection of hair follicles is another possible explanation. Regular exercise will improve your health and skin tone. Get HPV vaccine. Wish you good health!