Question about leg tiredness

[simurs4]

Hey guys went on a ride from Chelsea to Somers today to meet up with my parentals etc for a family thing, hadn't ridden down that way so i wasn't sure what i was getting into, was about 42km there with alot of steady inclines some steeper then others but my legs felt great the whole time going there, powering up hills off the saddle seemed easy but didn't want to over do it as i knew i had to ride home later on.
some of the roads getting there where pretty shite so i thought id take a different route home, which ended up being about 50km's in the end, felt alright for the first 15km or so but starting hitting alot more steeper and longer inclines and my legs suddenly decided to pack it in, lactic acid was building up pretty much as soon as i would start pedalling to make it up hills to the point where it was unbearable that i had to rest, but straight away acid would build up again without applying too much effort and my vision would start to go weird on occasion like i was light headed and i would have to walk up a couple hills because my legs refused to pedal anymore. the whole ride home ended up taking almost double the time and i haven't felt this beat up since i started ridding. my mind was willing but my legs weren't up to the task. i had been eating enough during the day and had enough fluids so it didn't seem like it was a nutrition thing.
was my body telling me that i was trying to hard or above my fitness level? or am i just being weak and should've just HTFU through it knowing i could recover once i got home?
i normally do 25-30 km's every couple of days after work or ride to work which is 20km each way plus 80km+ on sundays which i generally don't have a problem with.
any advice would be welcome, as i felt so deflated and angry at myself during the ride home.
cheers.

[Mulger bill]

I'm sre more qualified peoples will jump in soon enough but one thing I can tell you is NEVER try to HTFU through lightheadedness, especially if it plays visual games. Ground surfing hurts.

[PawPaw]

go and get a medical.
you left out a lot of critical info like your age, medical hx, bodyfat %, diet, stress level, BP, family hx, intoxication level, etc.

[Big Lance]

Could be something as simple as your body needing sugar, dont beat yourself up about it maybe just try some different nutrition, different times of eating etc. I find the timing of when i do certain things to have a massive effect on my performance.

[r2160]

Have you done that many kms in one day before? You might have just pushed yourself too far.

By all means, go see a doctor, but maybe just more kms are the solution.

cheers
Glenn

[DavidTomic]

By all means, go see a doctor, but maybe just more kms are the solution.

More KMs is the solution to everything, isn't it?