Trying To Conceive, Low Sperm Count, Taking Zinc, Oligo Care, Ocarnix. Advice For Insemination Process?

hi, im Victor from Bangladesh. im at 33yrs 11months of my age. My wife is 33yrs 2 month. We have been trying since 3yrs for baby. I have seen 2 doctors. They didnt found any major problem. Earlier my sperm count were 40million and there was some infections . I cured from that. And then its been long time we tried naturally. But didn t conceive yet. And then secondly we have seen another doctor, she found my sperm count were low like 10 million, doctor suggested some medicine, Zinc , oligo care, ocarnix etc. Then its increased again. but still now my mobility is 20%. Doctor advising some clinical thing, like my good qlty sperm will be placed to my wife s egg. Actually i like to do it naturally. Im really afraid and doctor said its have hope only 20%. So i dont want to be disappointed and waste money with no result. So please advice. If need i can send you some report if you required. many thanks for your attention. with best regards Victor