I can not get my firestick to connect to the tv. It worked fine before, now all of a sudden it isn't working

The TV might have lost its channel settings and would need them be rescanned and stored. Hope this helps

This will mean that your TV will only accept 1 HDMI signal through that port meaning a splitter won't work unfortunately.
The only other option is to get an adaptor for another port that you do have spare on your TV, like AV or DVI.

not sure if this will help
How to fix sound Kodi Firestick Disable bad feeds

their are other company;s that have a firestick [ Amazon ] others are directv --roku--google--apple etc most are plug and play this link definds some not all that are available
Your TV isn smart enough Why Roku Premiere is the best way to stream

Hey, there are couple of ways to download as well as installing Kodi on Firestick. I am not sure which method you used to download Kodi. I would suggest you download Kodi using ES File Explorer and then it will show install button as soon as download completes.
You can also check this guide - https://www.firesticktricks.com/install-kodi-on-fire-stick.html

If any further issues, please let me know.

I have no experience of these but as they work by connecting to the internet nothing is live in the conventional sense but streamed either from a single or a series of websites the firestick is programmed to log on to. The website(s) will usually provide a mixture of "live" tv, catch up tv available for a limited time, archive material and special programming and some movies.

What you get will depend on what is available free and what needs to be paid for, your internet/wireless connection and how good you are at reading instructions and operating the remote, assuming the firestick is working correctly.

A friend had a problem with connected tv and it turned out some of the sites took a long, long time to load and he was impatient and assumed it wasn't working.

heave ho away it goes

Perform one or more of
1. re-insert the firestick.
2. Power cycle the TV
3. renew the lease from the router (if not dynamic dhcp)
4. power cycle the router (as last resort)

suspect the firestick may be getting weak signal from the router.