I was wondering if there are any strong and durable converters out there for a quick release skewer to convert to a thru axle. I ride a MTB and need something that won't break or fail for me. I don't want to buy a new fork that fits a thru axle after buying a new wheelset.
You can't convert a QR bike to use a TA, sorry. Not without welding anyway.
The frame, specifically it's dropouts, control what you can use to retain the wheel's axle.
To use a through-axle, the end of the axle has to thread into the frame/fork, which has a threadded hole and not a dropout.
So the only option is to buy a frame/fork that uses a through-axle, and a compatible wheel hub, along with the axle itself. Be aware there are multiple standards and lengths, but a frame/fork should come with a suitable axle.
What might be confusing you is that some wheel hubs can be used with a QR or with a through-axle depending on which caps you fit to the outside.
If you're worried about QR on MTB you don't need to be - or at least not very much, and not if you take sensible precautions.
As mentioned in the comments, QRs on MTBs were standard for decades.
I would suggest though that you look at the type/quality of your skewers. I upgraded my skewers from external cam to internal as the former tended to loosen. This happened much more at the back than the front and the back doesn't have lawyer lips to keep the wheel in, so I came rather too close to losing the back wheel landing a very small jump. With a good (Deore XT) internal cam skewer, that issue has gone away.
Unfortunately MTBs that sold with QRs recently were inherently built to a budget, and tend to have cheap external cam skewers.
I'm also fairly heavy and the only bent axle I've ever had was on my tourer, not my MTB.