Straightening it 4 times a month is still once a week, which is still far too often and will lead to damage, especially if you're not taking precautions like deep conditioning before and after, using a heat protectant, being gentle and doing quick passes, making sure hair is fully dry before flat ironing, letting hair air dry instead of blow drying it beforehand, not having the iron on high heat and doing a protein treatment afterwards. I flat iron once a month at most, and I have still noticed some damage, and I do all of the above.
As for relaxer, well, all I'm saying is say hello to dry, lifeless and damaged hair. It's better to just accept yourself naturally, really. I am very busy also, don't spend much time on my hair and it looks great. And when it doesn't, I just throw it back. No biggie.