Hi thanks for your question
You have developed itching following visit to a beach, few weeks ago.
The itching is still persistent and leads to bump formation, on itching
You think it is due to bug bite
You may be right, it could be due to bug bite.
Bump formation after itching is normal, as this due to histamine
Have you taken any treatment for itching, I presume no.
Take antihistamine and short course of antibiotic ( since we presume this is bug bite of few weeks duration).
Hope fully you symptoms will subside in a week time.
Consultation with a physician is encouraged.
There are negligible chances that it could be a STD(sexually transmitted disease
Hope this answers your question.