Okay, since miners get a reward (bitcoin) for mining and help support the block chain, what will happen when the last bitcoin is mined? What incentive is there to mine bitcoin and thus support the block chain? Won\’t bitcoin crash at that point?
No, miners will be rewarded entirely from transaction fees which would be much higher per block due to bigger blocks (this was Satoshi's vision).
The price will also be EXPONENTIALLY higher than it is today, which means the effect of losing the block reward will be countered. This is already the case with every block reward halving, where the price is at least double when the block reward halves than it was at the previous halving.
This has been answered numerous times before, please search next time before making a new thread.
This is one of the "fee market" theories that has not been proven at all. It is just accepted without question. The fear of this is what has led to Bitcoin core developers to restrict the blocksize to 1MB in order to force the "fee market" to raise fees to eventually compensate for the missing block reward. The idea that one can increase fees by increasing the blocksize defies the most basic rules of economics. One does not increase price by increasing supply.
The most simple solution is to have a permanent block reward that does not fall to zero. This is what Monero has done with a minimum 0.6 XMR per 2 min block. For the Austrian hard money purists this is less than 1% per year and below the historical inflation rate of gold. Gold of course being the "gold standard" for hard money. With a minimum block reward then one can create an adaptive blocksize limit (Cryptonote / Monero) since a "fee market" is no longer necessary to secure the proof of work. One of the lessons from Monero is that this leads to a situation where the total fees collected per block is proportional to the block reward. If the block reward were to fall to zero then so will the total fees collected per block.
Monero takes advantage of this to set fees! Now for the critical part.
Any blocksize scaling solution that has a penalty that is equal to or lesser than in severity than the quadratic penalty for increasing the blocksize in Monero, in a coin with a finite number of coins.will lead over time to an insecure coin with the hashrate falling to zero. This would apply to Bitcoin, Litecoin, Dash, Zcash etc but not to Monero or Dogecoin.
Sorry but you have misunderstood the idea of fees and how the rewarding of the mining is done.
Once the block reward is 0 (near 2140) the fee will be forced (now it is forced just for the fact that if no fee your transaction may not get into the blockchain, as there are plenty of transaction that pay fees).
So when the block size is bigger there will be more transactions per block thus more fees in total will be collected.
So let's say today the normal fee for a fairly fast transaction is: 119435 satoshi, but one block can have only 1mb in this moment (average 2500 transactions, depends on size not number of transactions, so I took the day with most transactions 350k and devided it to see the average transactions per block for that day).
so 2500*0.00119435=2.985875BTC in fees.
If the size gets bigger, then much more transactions will get into one block => more money for miners.
example: BCH has 8x limit, so if by then BTC has made the size that bit (there must be consistent amount of transactions to force it to grow that much, but let's say it has happened)
then we will have 23.887 BTC reward...
And here is how increasing "supply" will increase profits.
Just like if you are fare service and you got only one bus with 10 seats, you will make less money then having 10 buses with 40 seats...
.In future since the block size has increased,we could transfer more coins per block which means more transaction fees and that is how the miners will survive. 
