Today fourth time I increase fees which is now 5612 Satoshi $1.98 40.0 sat/vB it's nearly two hours lurking in last three blocks but still not having 1st confirmation any solution or guideline for this could be appreciated.
If you increased the fee to the 25sat range yesterday itself then your transaction could have been confirmed because there were times when 21sat TX was included in the blocks for a while.
Even now your TX will be included in the next block if you can increase the fee to 45sat/vb or you have to wait longer cuz the network is highly congested and often fee sky rockets to 100sat/vb.
Look at this chart to know where your TX is queue: https://jochen-hoenicke.de/queue/#BTC,2h,weight
Or just use https://mempool.space/ for a simplified view.
With 40 sat/byte you should expect your transaction to get confirmed soon, or you can increase the fees a bit more. See here: https://mempool.space/
The estimated time is based on the current network congestion but no one knows what fees will be used in the upcoming TX so it's normal to hang around at 2 blocks from the tip region in these situations.