I don't think you can ever get rid of FOMO. It is always going to be around no matter what you do. The key is to just invest whatever you think you can afford to potentially lose and then just forget about it until a future date. One of the best things you can do is to simply look at it as a savings account and maybe take $50 from each check and put it into BTC or something like that. In that way you are averaging your buy in through the ups and downs of the market.
Hopefully after a year or two the price will be significantly higher and you won't really care about how much you bought when, you will just know that you have a lot more money now that you did then. That is what I would do. In the US, I probably wouldn't buy much less than $50 per time because the fees are going to basically eat into your whole purchase. For example buying $20 at at time will probably only give you about $15 worth of crypto after all of the fees and stuff like that.
Don't think it is a bull run Again Pump and Dump Drama going on. $400+ Dump for bitcoin which must have liquidated many risk takers and now again moving up ! Its just process to swipe out people and grab there Bitcoins !