Travel in Bangladesh (Dhaka)

Hello, I just arrived in Dhaka and I'll only be here for 6 months. I would love to see the country while I'm here and travel to different regions. Unfortunately, I don't speak Bangla, so I would like to travel with a group. I don't know a lot of people, and most tour companies i looked at cater to private groups. Are there any good tour groups or companies in Bangladesh that offer group tours so I'm not travelling on my own? In particular, I want to travel to different cities and regions for short trips on weekends and holidays. Thanks for your help!