Headaches in the back of my head for a few days?

So this started 5 days ago when I did a set of deadlifts in the gym. Not too heavy but my stupid self forgot to breathe enough during the set, which caused me to get a sharp headache and light headed etc like usual when you don't breathe during weight lifting. Anyways, I got it the next day again while benching when I did breathe, so I took the next 3 days off. I was lightheaded and slightly blurred vision for 3 days, nothing huge, was able to play soccer and drive without noticing it. It only came on while I was sitting around. Haven't gotten a headache in a day, now I just got a really bad one in the back of my head (where they all have been) I'm a natural anxious person, so I jump right to 'I have a brain hemorrhage or tumor' but I just don't know. Should I see a doctor ASAP or give it a day or two?