with no formal training, I have seen far, far worse
As others have said, movement is a big part of sparring/fighting, and its worth thinking about that now, rather than 'unlearning' bad habits later.
I would also suggest a little more visualisation in the structure of your striking.
By this I mean that at the moment, you just keep firing punches off in an almost non-stop super-long combination, with little feel for the timing or movement of the bag. All your punches are also thrown to a 'comfort zone' that equates to chest height on an average size oponent.
It feels great to lay in to a bag like this, but unless you are Manny Pacquiao, it is not going to work against an oponent
Try and see a person, not a bag, move and pick shots that maximise impact based on the relationship between you and the bag at that moment, bob, weave, get your chin behind your shoulder, expecting the bag to punch back, and switch ranges and targets from head to body as dictated by how you read the motion of the bag. Use this to create a rythm of crisp focused combinations of no more than 6 consecutive punches (unlikely to be able to throw more than this uninterupted against even the poorest of oponents).
This will help prepare you for more structured training in the future