Please go see a doctor right away. The sooner you go, the sooner you will get better. Please don't waste time worrying. Find a doctor as soon as you read this.
In America, we have Hospitals, we have "Urgent Care" centers, and we have "family physicians."
I just read that you have something similar in India: "The Federation of Family Physicians' Associations of India (FFPAI) is an organization which has a connection with more than 8000 general practitioners through having affiliated membership."
Find a doctor that can see you within 24 hours.
Your sexual behavior is your business and it may or may not have resulted in your symptoms.
We cannot diagnose here. Your symptoms may be treated with OTC remedies in your local pharmacy, but I wouldn't suggest you self-medicate for constipation or a UTI.
Seek medical attention, now. You may be exhibiting symptoms of a lower abdominal infection that can quickly escalate to more serious problems.
Best wishes.