Pain in my big toe 6 years after tendon repair?

I severed the tendon running across the top of the joint on my big toe 6 years ago and had it repaired. It healed with a small bump and has caused me no problems until the past week. I have had sharp stabbing pains in my toe where the bump of tendon is every time i wear flip flops or sandals that run across that part of my foot! I have now noticed it is tender to touch aswell. I just wondered what it is seeing as i have gone so long without any problems at all and what i can do to help it, except for not wearing sandals this summer! I'm wondering if the fact i've lost alot of weight and my feet aren't so fat has something to do with it aswell! Can anybody help? Thankyou