Gunpowder has been around for centuries at that time period, plus oil and other flammable substances already exist. If your enemy have access to such technology, your tank would be just a big moving target.
you are forgetting that any tank without support is a big moving target and so my tank isn't an exception to that rule meaning that unless you kill the infantry support my tank can still do damage
Problem with that is your tank will only ever traverse on paved roads, which limits where you can actually deploy them. Surround them with infantry is just going to make it an even bigger target. You essentially need this take to be thrown into cities where it is extremely hostile to any vehicles.
I think the best way to make this tank battle capable is by giving it an SPG (Self Propelled Gun) role, due to gunpowder cannons needing lengthy reload time and (some) are pretty heavy if you don’t have horses or a bunch of guys wheeling it around