Thanks for your query.Based on the facts that you have posted it appears that you have repeated episodes of UTI and now you have itching and your labia is swollen and red suggesting active fungal infection
called as Mucocutaneous Genital candidiasis
This being very common in diabetic individuals.Please get your blood sugar level tests done to rue out diabetes
Please take anti fungal medications like Fluconozole along with topical anti fungal jelly for local application over Labia Minora
and Urethral meatus twice daily.
Get the prescription of medicines from your family Physician.
It should get cured with this treatment.