I have the same problem. I'm using Oxford talking dictionary to improve word pronunciation. there are many English talking dictionary.I think you may try.All the best.
OTT said there was 'something wrong with your S's'. I imagine a more useful way to put this is that there's something Spanish about them. The Spanish s is typically (in Castilian) pronounced with the tip of the tongue; the technical word is 'apical' - but don't go around saying you've got an apical s because only students of linguistics will understand you. ;-)
If you want to change this, slide your tongue very slightly forward. But be careful: a lot of Spanish speakers do this, and take it to far, producing a /θ/. Just rock the tongue, so that instead of a | it makes a \; that is, the angle between the tip of the tongue and the back of the gum is less acute.
But, as others have said, accent is something that doesn't matter unless it interferes with communication.
Just one point on pronunciation in general - up to a point it's true that it doesn't matter so long as people can understand you, but that's an oversimplification.
Firstly, this "test" has the problem that when you "fail", it is pretty much impossible to do anything about it immediately. You maximise the probability of not "failing" by minimising your accent as much as possible.
A corollary of this is that accents cause non-native speakers much greater difficulty than native speakers; so the more globally you want your English to be understood, the less accent you should aim for.
Secondly, a large part of the world is not as tolerant as those of us posting here. Accent is something about which people make judgements - OK, maybe they shouldn't, but it's pretty much subconscious, so it's going to keep happening. BUT, the good news is that if you have very little to no accent, as anon-native speaker, your prestige will be great & people will generally be very positively impressed.
Everything n language learning depends on your goals - but I would say, keep working on the accent.
If you want one simple tip, pick an actor whose voice you like, and copy that voice. Accent-modification is mainly an exercise in accurate listening.
The videos are a great idea.
You accent is the typical spanish one. Between the english and the american, I could say that you are closer to the brittish.
Good anyway, I understood everything so just a little bit more practice and that's it.
Thank y'all! Especially BobK; I'm already improving my s sounds.
It's been a long time, but I just came back to thank you folks and tell you I uploaded... yet another video! Yes, I know. I talk about the australian accent, which I love, and I ask for some tips:
YouTube - My accent and the Australian Accent