Streamline taxes

I need to streamline my last 3 years of taxes.. Admit it's my own fault.. Been here 24 years this year and have kinda forgotten about that obligation.. I know I know....

Now comes the queries...
Have done some good ole google searches and most of the expat taxes websites are  much more than I can afford to be honest.
Can I do this myself? 
How difficult would it be??
Any good websites to consult?
Any advice welcome
 

Based on the limited information provided, you are most likely due a refund because you have not yet claimed the Covid stimulus refunds.

You are 100% correct, there is no need to pay for a professional, all the official forms & instructions are available for FREE on the official IRS website https://www.irs.gov/ and with FinCEN here: https://bsaefiling.fincen.treas.gov/NoRegFBARFiler.html websites. If you prefer software, the IRS offer several free filing services: https://www.irs.gov/filing/free-file-do-your-federal-taxes-for-free. The IRS also offer a great deal of excellent free information including videos: https://www.irs.gov/individuals/international-taxpayers/taxpayers-living-abroad

My understanding is you only need to streamline if you owe taxes. If you prepare the returns and don't owe any taxes just file them - and if you need to file FBars do those under the delinquent Fbar submission:

https://www.irs.gov/individuals/international-taxpayers/delinquent-fbar-submission-procedures