You shouldn't be worried about mistakes. Embrace them. No matter what, when learning a new language, there will be many errors in your speech and writing. Don't be ashamed of it! Be proud of it. Try to make as many mistakes as possible so that you can learn new things when your mistakes are corrected :) 

Good luck and, more importantly, have fun with it!

You know... as they say "practice makes perfect".

Start with something you can handle.

Try audiobooks with something you know

Research shows that the more you read, the better your English language becomes. Reading in English improves your listening, speaking, reading, writing, pronunciation, fluency and confidence.Download Duolingo app. Chat with whatsapp .... anything you like...

And as one of the most quoted personalities ever, Confucius, says "I 

hear and I forget. I see and I remember. I do and I understand.” and "

Wheresoever you go, go with all your heart.". =D

Here's a trick. 

Find people that are native or really good at speaking in English but are bad at Tagalog or can't speak it at all. Then while you are speaking English with them you can keep telling yourself how great you are at it compared to how they speak Tagalog and how impressed they are going to be with how you know English when they don't know your language! 

You speak English much better than I speak Mandarin or Sanskrit. :D

Find kind and patient people to practice with. There are lots of them! I bet most of the teachers here at Italki are like that. You need a good cheerleader.

Also, when people are afraid of public speaking in America they say that you just have to imagine that the person you are speaking to is in their funny looking underwear to make you laugh a little at them, and then you can relax. 

Another suggestion is to find some songs that you like in English and keep on singing the songs just like you hear them. That can really help with practicing pronunciation and improving your confidence. Music can relax the nervous system and give you some new associations with the language of happiness and joy. 

The more relaxed and joyful you can become while speaking, the better your pronunciation will be. 

I don't understand...what's wrong with your English? You can express freely in English a lot better than our parents and grand parents generation. Its not so hard for us, grammar yes but no limits how we communicate and express ourselves. Give yourself more credit. Nervous? Try taking public speaking class, and it scares me.

I honestly think that if you keep on speaking with a native speaker and watch English movies, series etc., you'll feel more comfortable. Try to copy the way they speak and practice speaking aloud when you are by yourself, then carefully listen to the way you speak. It's natural to make mistakes. Even native speakers make mistakes.