Don't buy immodium; generic loperamide are roughly 10% of the price.
As for myself poppy seed was far too hit and miss; all it takes is for some well meaning ingredient supplier to wash your seed and you've just wasted money. Do you live in a country where it's legal to grow opium poppy? If so, poppies are a popular plant for gardeners; you could simply harvest whichever plants you find under the cover of night. This is how I do it in the UK, and I always look forward to "opium season".
Of course, you need stuff to help you combat opiate withdrawals, and there are options available to you. Kratom could be great, loperamide, kava and also RC benzos such as etizolam, pyrazolam, etc (these are addictive, don't use them for more than six days, and be careful to take less each day; 20% less per day is a good rule of thumb.) If these are illegal where you are, I've heard phenibut is useful for opiate detox. It's important you cycle your use carefully though, as it's tolerance buildup is rapid.