If it doesn't show the old balance then try to resync by closing your Electrum and open it again. If it still doesn't work try to turn your internet/wifi off then open it again.
Anyway, your transaction is 10sat/byte I think you can try to submit it to
https://www.viabtc.com/tools/txaccelerator? to speed up the transaction. If this doesn't work for a couple of hours and the above suggestion doesn't work then your last option is to rebuild the transaction.
You will need this tool
https://coinb.in/#newTransaction then paste the TXID and load. Now change the transaction fee use the recommended fee from this link
https://mempool.space/After you submit, copy the raw transaction and import it to Electrum and then sign and broadcast the transaction.
Unfortunately, none of the above works. Tried restarting Electrum, Wifi - the transaction does not and will not appear in the history tab.
When I post my TXID into Coinb.in, I am able to load the transaction succesfully with all the addresses. However, when I click "Submit" I get a massage saying "One or more input or output is invalid". The "Inputs" tab is flashing in a red color.
I am pretty sure that my BTC is lost. Or am I wrong?