Utter Confusion.....

I think I am losing it. First, I did something that screwed up my gmail page...well, gmail no longer shows up on my Firefox start page....and Firefox unfortunately gave me THE LATEST...which just screws me up further. Now I have to sign out to get back to where I was every time I do some foolish thing like enlarging a photo.....there is no longer a 'back' button up in the left hand corner of my 'page'...only an arrow in a circle, an X, and a house.....none of which will let me go BACK. Oh, good lord....am I going to have to shut myself away for a week and read all the stuff about Firefox and Mozilla and even Google and gmail? It was all so easy before they started upgrading me all the time....I don't want to be upgraded......I just want to do all the nice simple things like hitting an arrow facing left and going BACK. I finally caught on to the menu bar where they show me where I am and discovered how to hit that to get rid of a page....but it doesn't show anything for when I do something like enlarge a photo.....or a couple of other things....so I have to go out of the damned program and start all over again. It was very annoying when I was online writing to friends and had to do all that....disappearing for quite a time with everyone wondering what happened to me. Well, I didn't tell them....let them thing what they will. Now I MUST go to bed.....I'm a Mac person, we don't like to read manuals....Ah, well......