The colourless thing which smells very bad is known as smegma, Which is a normal physiological thing for that you don’t have to worry just clean you are area with clean water twice to thrice a day.
For itching nd swelling You may be suffering from localised fungal infection which is very common kindly consult with the history and picture of the area so that I can guide you further on the treatment part.
Next Steps
For further clarification, complete evaluation, correct diagnosis and treatment and prescription feel free to consult me on this PRACTO APP. Stay safe and take care of yourself