Massive 400,000 coupons and now causing high oer load on server and extreme sl

Dear admin of this great plugin.
We decided to try out your plugin and found out its great. Only did I know this would cause a huge setback for our website performance.
Our site is operating on 2 DEDICATED SERVERS with 16 CPU CORES each for the webserver and DATABASE. We got to observe that since creating over 400,000 COUPONS with this plugin, the site was ultimately and extremely slow.

On checking, the DATABASE SERVER. we got the following results which is currently affecting us:

root@mysql ~]# top -H

top – 12:34:47 up 6 days, 11:05, 2 users, load average: 32.71, 34.69, 39.46
Tasks: 528 total, 43 running, 485 sleeping, 0 stopped, 0 zombie
Cpu(s): 86.1%us, 12.3%sy, 0.0%ni, 0.0%id, 0.0%wa, 0.0%hi, 1.5%si, 0.0%st
Mem: 10120336k total, 7859684k used, 2260652k free, 182484k buffers
Swap: 4095996k total, 0k used, 4095996k free, 6448320k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
35108 mysql 20 0 1898m 703m 12m R 19.9 7.1 0:01.74 mysqld
35104 mysql 20 0 1898m 703m 12m R 19.3 7.1 0:01.71 mysqld
35117 mysql 20 0 1898m 703m 12m R 19.3 7.1 0:00.79 mysqld
35111 mysql 20 0 1898m 703m 12m R 18.9 7.1 0:01.65 mysqld
35080 mysql 20 0 1898m 703m 12m R 18.6 7.1 0:02.25 mysqld
35065 mysql 20 0 1898m 703m 12m R 18.3 7.1 0:01.68 mysqld
35134 mysql 20 0 1898m 703m 12m R 18.3 7.1 0:00.73 mysqld
35053 mysql 20 0 1898m 703m 12m R 18.0 7.1 0:04.17 mysqld
35121 mysql 20 0 1898m 703m 12m R 18.0 7.1 0:01.79 mysqld
35133 mysql 20 0 1898m 703m 12m R 18.0 7.1 0:00.76 mysqld
35126 mysql 20 0 1898m 703m 12m R 17.6 7.1 0:00.71 mysqld
35127 mysql 20 0 1898m 703m 12m S 17.6 7.1 0:01.07 mysqld
35136 mysql 20 0 1898m 703m 12m R 17.6 7.1 0:00.65 mysqld
35141 mysql 20 0 1898m 703m 12m R 17.6 7.1 0:00.76 mysqld
35094 mysql 20 0 1898m 703m 12m R 17.3 7.1 0:01.71 mysqld

This is extreme overloaded. The site calls the MYSQL TABLE OF over 80MB which is extremely heavy.

I would like to ask because, how can we reduce the 400,000 COUPONS generated with you plugin to 20,000 because its affecting us and we are paying heavily monthly to main the site due to this. In addition to this, the site is extremely load to respond.

Please help!