You really need to start paying attention to the forum. The best starting point is the stickies. But anyway:
1. Yep, you probably had those txs dropped. If it's not in your history and you can't find it on blockchain explorer, then they were never confirmed. What happened: your fees were too low, miners never picked them up. Nodes eventually stopped broadcasting them (or your wallet stopped doing it), and the network no longer knows of their existence.
2. That's good for you! Now you can read the sticky and start afresh.
3. Use manual fees. And use an estimator like
https://bitcoinfees.earn.com right at the moment you want to spend. Add the fees, maybe bump it up by 10 sats/byte. It's not 100% accurate, but it's always helped me.
4. To benefit from Segwit, you must use a SegWit address to spend the coins.