It's very difficult to write a chess bot that plays like a human. They've improved in recent years in their human-ness but will still make very obvious mistakes that a human player is unlikely to make even at low Elo. This makes them a fairly poor substitute for real players if you want to practise and improve.

Rating anxiety is also common in games that have rankings systems. There are various strategies for avoiding rating anxiety, but you could try setting yourself your own goal such as "I'm going to play 5 games against human players regardless of the outcomes" and try to disconnect your performance and rating from your sense of accomplishment. If you analyse your losses and learn from your mistakes then even if you lose you are gaining something, so you should have less anxiety about losing before you start playing.