You should hold because there is a reason behind, Segwit and Segwit2x will raise the user confidence by expanding the blockchain block size from 1MB to 2MB. The Blockchain processing will be more optimized and in a result user will feel more satisfied hence a increase in the value of asset.
No.2 The awareness about the bitcoin network and its easiness of use in markets and money transfer will create some more interest for the time being and when public will take interest, bitcoin will be taking a young asset and hence increase in the value.
No. 3 My personal experience: When bitcoins crossed 630, One day before when I was trading it in a range of 570-600$ per bitcoin. I feel the same danger like you, I thought that this is the top price of this asset but all of us saw it produced straight 480% increase in the last 8 months. A huge one.
I predict 5000$ per bitcoin will come very soon. Let's See and HOLD tightly your bitcoins.