Try here:

https://www.khanacademy.org/science/chemistry

I think of chemistry as a cumulative bag of tricks. One trick requires that you know a previous trick. If you miss a trick then later tricks are incomprehensible...

I find it hard to get motivation when things seem hopeless... It could well be the case that your teacher simply isn't able to explain things... Lots of chemistry teachers... Aren't very good at explaining the tricks...

It is easier (so very much easier) to find the motivation to watch a short youtube video. You should be able to learn the tricks from here and then have much better luck with doing the problems your teacher has set.