Please help.
 

I have a 2016 Honda Fit EX (Stormy) . It stopped on me for a while I needed a battery so I was jumping it every time I used it. I replaced the battery and nothing happened. Nothing came on. I was advised to change some of my fuses, did that and the light around the speedometer came on but still won't start, lock the doors, nothing. My key is kinda (alot) broken idk if that may be a reason, can someone help me please. Thanks

A few of them, so I changed them. An the front part of the key isn't on there. Like it's barely held together

No I just changed them today. Polarity?
What should I do about my key? The headlights won't come on niether will the blinker. But when I turn the lights on it makes tgt ding noise, the brrbr lights come on though.

* Brake lights

If your key is incomplete, yes, that could cause starting problems.

The primary concern is to get the car running on its own without a jump. If you don't have a spare key, I'd start with a freshly programmed key, to eliminate the key as the source of your problem. You'll need a complete key going forward, might as well get it done now.

If you don't want to go to a Honda dealership or aftermarket repair shop, I believe many locksmiths can program a key for you, sometimes at lower cost.

If you can lock/unlock your door, and you are able to turn to accessory mode on, you might want to take a look at the starter if you hear "click, click" but engine won't turn.

Well, those two things make diagnosis very difficult.
At this point, hard to know whether your continued problems are battery related...fuse related...or key related.

You seem to suggest that before battery replacement it was working fine...with a jump start. Which would make me think the key, WAS working fine.
But since the battery has been replaced, and now you are still having problems, I'm not Wizard enough to know where your problem is manifesting.

Things can snowball. And at this point, it could be the battery, maybe not installed right or connections loose, or it could be fuses blown, or it could be the key.
At this point, I think the easiest answer would be a competent mechanic that can simply rule out what it is NOT..and thus lead you to what it IS.

Over the internet, simply from description of symptoms and admission of a "kinda" broken- a lot key? I can't give you a solid diagnosis.

I hope it turns out to be the simplest and cheapest of possible solutions.

Whatever is discovered, I'd probably want my key fixed or replaced anyway.

Good Luck.