Use p2pool
Monero Mining
Your hashrate doesn't get lower if the difficulty changes, perhaps you reverted some RAM overclock setting by clearing the BIOS?
I too would recommend you mine to p2pool mini as you should see payouts rather quickly. 2 Months of 18.000 h/s and 0 XMR is definitely wrong.
We are all about decentralization here so everyone will tell you to use p2pool. Mining on someone else's server is meh. There is an easy to use GUI if you are not too familiar with command line @ https://gupax.io/
P2pool requires a monero node, because you are really mining and creating blocks. You can use a remote node if you do not have your own, you should have your own anyway though.
With p2pool there is no need to worry about server locations because it will automatically connect to fastest peers, plus it never goes down and there is not "payout issues" because you get the actual coinbase.
Try p2pool, I get several payouts a day with that hashrate. Bonus because theres no pool or transaction fees, and its better for the network.
Oh my Gucci- I just got a payout with the Monero GUI local node + miner, using P2Pool Mini! This is the first fruit of my labor! Seizure for Jesus, I finally did it!
what about just solo mining? is that not a good option for OP?
chances of finding a monero block with such a low hashrate may leave them mining for months with no payout, I would not even attempt solo with anything lower than 100 kh/s