Bangladeshis always hated us. They were the first to support the idea of Pakistan when the western side didn't support. The first riot started in Kolkata during the direct action day. It is a historic hatred. They just used us in 1971 to get rid of Pakistan from massacring them.
Not only what you have said, we have also formed All-India Muslim League in Dhaka in 1906. The muslim leaders from all over India, after a long and painful journey, came to Dhaka at the invitation of Nawab Salimullah and in order to defend the interest of the Muslims they formed this League, that, at a later time, established Pakistan.
Now, you have to find out the background so as to why the Muslim leaders had to establish ML. Read the history to know how our elite Hindu Bangalis were treating us since after the Battle of Plassey. These Hindus were borrowing power from the colonialist British and were bullying us.
History forced us to demand a separation from these Bangla speaking cousines of us. These Calcutta elites are distrusted by us, and unfortunately, this distrust extends also to other Indians as well. It is because these Babus belong to India.
On the matter of Muslim separation efforts from the Hindus, once Rabindra Nath Thakur commented, "Why to complain when a person you hate also starts hating you.?" As far as I know, these west Bengal Babus are equally hated by also other Indians, too.
Finally I must say that the attitude of Bangali Hindu Babus was responsible for the partition of India and Bengal. So, do not blame us, because we wanted only to save our skin.