Recent activity doesn't show everything you do/did. I believe it only shows stuff like top 1k rank scores or something.
Anyway like the others said play more, u barely played for 4 months "activity"
Play whatever maps u want. That's what I do, I don't always get pp, in fact I barely got any pp for the last 2-3 months. But that's because I play maps that I can't FC or nearly FC. But that doesn't mean I am not getting better. You just have to play stuff slightly above your own skill (if u are able to judge it properly) personaly I try to play stuff that gives me problems so I can fix that problems.
If u have problems with streaming, play maps with streams, if u have problems with doubles/triples play them..., if u have problems with sliders w/e variation for the love of god play them.
Don't avoid stuff u are bad at. Play it and get better at it. That's all there is to it imo.
https://osu.ppy.sh/u/4974611If u check my profile u can see I did some scores recently but recent activity doesn't show me anything.
Also, don't play maps u can't even pass. Smashing keyboard can be fun for a while but u won't get better if that's what u're aiming for. Accept the fact that u can only play up to this or that difficulty. Even tho star rating is pretty fucked up for some maps.