Do I need to stop my sildenafil because of these side effects??

Hello so I have pretty bad anxiety which created performance anxiety so I was given sildenafil 50mg by my gp

I’ve been taking 2 a week for around 8 weeks now, I take them mainly on the weekend 24h apart. When I take them I feel my skin go hot on my head and a blue tint in my vision which I know is common but the other side effects I get are about more worrysum

Around 10-15 mins into sex if it gets that long is when I start to have bad symptoms. My heart will pound really fast, I’ll sweat a lot and I feel a little lightheaded. Kinda like I might pass out if I continue so I have to stop just incase, I’ve never actually passed out though & the fast heart rate instantly calms down if I stop.

I’m wondering if this is a sign of something worrysum or not? Could it be my anxiety contributing? I have had many heart tests in the past, last ecg was only a month ago which was clear, also had bloods, CT scan and X-rays over a year ago all clear so I think as far as I know my heart is fine.

Just curious to weather what I’m experiencing is normal or not?

28 male