launcher wont load me into the game

Put the summary of the bug you're having here so i was playing minecraft then i get very bad lag spikes then i restart my computer thinking it is not going to lag then i try to play minecraft and it wouldnt let me play so i didnt know what to do and i have been looking at things on the internet to try and get it working for a long time so could u help me

What I expected to happen was...: i just wanted to play minecraft lag free
Describe what you thought should happen here i
i thought that i would restart my computer and i would be able to play minecraft lag free
What actually happened was...: is that the launcher isnt taking me past the launcher bit where u choose your profile
Describe what happened here

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ... load up minecraft
3. ...then press play and it wont load me on the minecraft