America boyfriend, wanting to live together. where to start?

Hello im new here and i dont really know where to start and i would apreciate your help alot...

Me and my boyfriend have been together for 2 years and i intend to go visit him in Texas.
I know i will need a waiver visa (im from Portugal) and i will only be able to stay there for 90 days or less.
We decided it as we love each other and plan to spend our lives together it was a good time to start living together but with these visa issues and stuff we dont really know what to do and where to start.
Their parents offered to help us pay for my college (its quite expensive if you are from a foreign country) so i could get a student visa but i wouldnt feel good with myself if accepted that so I was thinking about visiting him under the waiver visa stay there for like 3/4 weeks and then come back and having him ask for a fiance visa for me but as it will take alot of time to get accepted my boyfriend said he would rather marry me instead while im there and then ask for a spouse visa.
Either way i want to come back to Portugal and take care of my stuff before i move permanently but i dont really know how to make them believe during my interview that i do want to come back even if we get married, I dont have a job but i depend on my parents and im a college student.
Can i tell them i intend to get married and come back? Or should i just tell them im going there to visit someone? Is this considered fraud? I really dont want to mess it up because me and my boyfriend have been waiting for so long and its getting super frustating...
Also if we do get married can i still visit him while the spouse visa is pending?
I didnt want to rush things up but marriage seems like the only option, either way my intensions are good and i would never marry him if all i wanted to do was becoming an american citizen i even told him if it doesnt work i would come back since all my family and friends are here...
I would really apreciate your advice, thank you.

Getting a spouse visa is not a wise Idea. Because process takes 6 months, only you got 3 months to do anything in US(either marry or leave US). The simplest way of getting married in US is your boyfriend should apply for an immigrant visa for you by filing a form I-130 with the USCIS office at the American Embassy. You will be issued a green card upon entering US.

Worth considering... I heard it is best to get married at the USA embassy in your case in Portugal and submit the papers there as opposed to getting married in the USA. The process then allegedly goes much faster. Not sure, do research, just writing what I heard.