lm for multiple regression hangs up

I'm new to R and came over strictly to do a regression on a dataset with 28 variables and 60k entries (excel limits you to 16 variables). I watched some tutorials, read some guides, then wrote this script with the hope that I would easily get the results:

mydata2 <- read.csv("C:/raw.csv",head=TRUE)
summary(mydata2) #this will show the summary just fine
model1 <- lm(formula = total.return ~ x1 + x2, data = mydata2) #hangs up forever
I've also tried
model1 <- lm(total.return ~ x1 + x2)
Am I doing something wrong with the csv import? What am I missing? Thanks in advance for any help you can give me.