my iphone is a v1.1.1 fully unlocked phone. it is jailbreaked too. I am facing some problems with the wifi. Cant detect wifi and lose connection easily.

i tried to connect to my home's router and i need to be very close to recieve a detection of the network ( it's unsecured). whenever i get connected the wifi bar is full as soon as i start to access youtube or anyother interenet apps it will drop to one bar or disconnect. when i step around 7 steps from the router i cant even recieve the detection of the network. my macbook which is in the other room have no problems at all in connecting to the router.

i tried all sorts of troubleshooting playng around with the dns settings and even changing the channels but to no avail.

i decided to proceed to a hotspot to try instead. my phone cannot detect any network at all. tried at starbucks and mac. nothing

Thus my verdict was something was wrong in my phone.
but is it the hardware problem as in the anthena is spoilt or is it due to the software problem. anyone facing the same problem b4? i would really appreciate any solutions to solve my problem!

thanks