Its really scaring, dont know what will happen if they touch 51% mark.
Absolutely nothing. 51% is not, in this case at least, a magic number. Double spend attacks are theoretically possible with much less than 51%.
Furthermore those in control of the 51% can not somehow magically destroy Bitcoin overnight. It simply means that they, in theory, could destabilize the network and perhaps scam some coins but A) that's massively not in their interests and B) as soon as some miners shift their hashrate to a different pool their evil plans are totally thwarted.
If you're actually interested in knowing and understanding: https://bitcoil.co.il/Doublespend.pdf
TLDR: The threat is real but the implications are often massively overblown. Learn more; worry less.
