Do you mean your 45k hungry, bootless, bulletless, coward army was going to subjugate 75 million hostile people for thousands of years in an enemy territory 2000 km away from home base? I think, you should thank your Indian brothers for saving your army from being defeated by an unconventional guerrilla forces had the war continued for some more times. Your Indian brothers were too restless to seize the once in a lifetime opportunity to achieve an easy war victory and taunt you for eternity. Had the war continued for one more year, then your troops would have surrendered to Mukti Bahini alone.
In recent times a mostly unarmed population even with greater numbers on their side has been successfully kept in line by force.
The scenario u r arguing could've been true in times like when American Independence happened. This is why u see the second amendment...during those times it was the British Army with muskets vs American militia with muskets. Based on this...the founding fathers included in the Constitution the right to bear arms and to be able to raise a militia if the government becomes a tyrant.
That is a dated concept that no longer works in practice. A militia today would have a hard time going up against a professional army, air force, and navy. That professional military can bomb the militia's location...at will...bomb entire convoys...enjoy complete air superiority...which is just one of the huge advantages that a militia can never hope to nullify. The numbers advantage disappears against strategic and tactical advances like the one described above. In absence of India's interference Mukti Bahini would have a hard time acquiring weapons and training. There would be no naval blockade of IN or aerial opposition of IAF...Pak would be able to resupply food, ammunition, and supplies unopposed through sea and air routes. The naval bases and ports...and airports critical to keep these supply routes open would be heavily guarded. This is assuming a full advantage of the likes of Mukti Bahini and other resistance elements on BD land...where they successfully manage to cut off all local food and supplies to armed forces. It would be a costly affair to keep supplying the troops(abroad in a sense) but doable. In absence of India's patronage of financing this separatist element when compared to the armed forces being backed by a country's economy...Mukti Bahini and other separatist elements would soon run out of juice and be forced to give up. It would end up being like the LTTE movement in Sri Lanka. When LTTE had no external support...it fizzled out.
So in conclusion...for the BD independence to happen...
You guys NEEDED India to finance it
You guys NEEDED India to arm and train Mukti Bahini and other such groups
You guys NEEDED the intel provided by India to carry out sabotage missions
You guys NEEDED India to intervene militarily to gain independence
These things aside...i googled BD population in 1971...and most sources suggest that it was around 65 million. Of these 65 million not all were physically fit young males(and/or females) ready for a fight...this includes everyone the young and old alike. Moreover of those who were able to fight weren't all onboard with the separatist ideology. There was a whole range of thinking from staying with Pakistan on one end to having a separate country on the other end...and everything in between. Many wanted to remain with Pak in the name of Islam or bcuz they wanted to work within the system to bring about change to address any injustices that occurred or be given more autonomy to manage their own affairs...etc. Taking all of that into account...u can see how there was no 75million hostile population u have come up with.
Anyways it is pointless to beat a dead horse. Whatever happened..happened. U can either keep looking back and define ur future on the past tensions and hate or try and move on and build a better relation with Pakistan...looking toward a better more hopeful future...
...and make no mistake(not u particularly but other pro India Bangladeshis) India is not ur friend. They helped out Bangladesh in their hatred towards Pak...and not out of some love for Bangladeshi ppl. India wants to be a regional power(at the very least)...so at least for their neighbors it means that either u stay in line and they dictate u...or if u oppose then u r their enemy. Sooner or later BD will find itself at odds with India...and it would be up to the ppl and ur leaders either to act as a vassal state or otherwise have enough power(militarily) to keep India at bay if u choose ur own path.