im desperate to understand,i seriously tried 

im new to iota but it is quite hard to understand how consensus is achieved in iota, and what is the transaction structure ? i also don't understand what is the role of weight and score , i understand how it works theoretically but how does the weight gets updated practically (what is the thing the gets transmitted in the network to update the weight) 

 and where does proof of work fit in(when is it used and why), it would be very nice if someone could provide a scenario or a diagram of how transactions are broadcast to finally getting approved by the network.

 in the case of blockchain it is crystal clear how consensus is achieved, it is also confusing how come you can have only a subset of transaction (not all transactions like blockchain) and still validate transactions, isn't it necessary to have a complete view of transactions history (similar to Blockchain,you need the full Blockchain to verify)

how do i know as a node which tips to choose if i don't store transactions? a scenario of double spending attack  would also be great, i know this is too much but i tried my best to understand the white paper and unfortunately it is very hard to understand.