You should look firstly at the visa question. After getting married, it gets much more than 8 months to obtain your visa (ie right to work). Make a few searches on this forum.
Now for IT question. Computer science degree from a US university is what all brazilian IT people dream about. So good start for you. In this field, you do not need to validate your diplomas. Your IT work experience in US will be recognized as non-existent. Brazilian companies love IT certifications (Microsoft, Networkk/CISCO, methodology, project-management and any software vendor certification). English is a plus but portuguese (fluent) is the most important. All together you will be in competition with all Brazilians. If you are young, motivated, persistent and ready to start from scratch, you have got some opportunities. But do not forget that brazilians companies have obligation to fill job for brazilian and motivate that they need a foreigner.
You did not say where you will leave. SP Paulo is the right place for IT; all other cities have much less opportunities.
This is very tought to find of job in IT (or any other field) when already in Brazil. All the foreigners who are employes came to Brazil like "expat" (a foreign company send them here). All other people actually created their own business (or give private languages lessons but impossible to live decently with that ...).
Your best bet is with companies where you already worked (or clients/provider who know you) and which operate in Brazil. Linkedin is well used in Brazil but more than anywere personal/face to face networking is the most important. Brazil is a place where people are known in business by their first name, even just a nickname. So it can happen only when meeting people in real. So you can make good contact online but find a job in Linkedin is difficult. All the time it will finished by "great, so let's have a chat when you are in Brazil".Â
From my personnal experience (good CV, IT manager, 16 year international experience working for biggest players in financial markets. quite well prepared for Brazil (speaking portuguese, culture, etc), but certainly I did not want to start from scratch and possibly I was older than you; I understood the best was to create by business. Tough also but this is my own business and rewards are bigger.